Merge branch 'docs'

Completely rewrite documentation, in preparation of the new release.
The README.md file was already a little inaccurate and desynced from the
last tagged git-sonar script, but now that the files have been
redesigned, documentation is in need of a complete face lift.

I've opted to move the meat of the user-facing documentation into
manpages, so that the high fidelity documentation is more accessible on
demand.  This also better opens the door for packaging of git-sonar down
the road, providing some form of documentation that will get 'installed'
along with the tool.

The output of --help for each script is removed, and instead --help will
recall that script's manpage using the 'man' command.  This is done to
make it more obvious that more verbose docs exist, as well as to reduce
the number of spots for documentation that need to be kept in sync.

README is stripped down to function as a higher-level project
information file, which is more focused and easier to navigate now that
usage documentation has its own home.

* docs:
  Replace README with new project information
  precheck: Add documentation in new manpage
  Update core documentation as git-sonar manpage

1 files changed, 498 insertions, 0 deletions

diff --git a/git-sonar.1 b/git-sonar.1
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--- /dev/null
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@@ -0,0 +1,498 @@
+.TH GIT\-SONAR 1 git\-sonar
+
+.SH NAME
+git\-sonar \- a heads up display for git
+
+.SH SYNOPSIS
+.B git\-sonar
+.RB [ options ]
+
+.SH DESCRIPTION
+git\-sonar is a tool you can add to your shell prompt to provide at\-a\-glance
+information about your git repositories.  This includes information such as the
+name of the checked\-out branch, a summary of the
+.B git status
+for modified files, the number of commits which may be pushed or pulled, and
+more.  See the "PROMPT ELEMENTS" section for examples of various possible prompt
+outputs.
+.P
+After installation, git\-sonar is activated by placing a call to the script in
+your shell's
+.B $PS1
+environment variable (or the equivalent).  See the "USAGE" section for
+additional instructions on setting up some common shells.
+.P
+git\-sonar's appearance can be customized by setting various environment
+variables.  See the "CONFIGURATION" section for an exhaustive list of supported
+variables and their descriptions.
+.P
+As an additional feature, git\-sonar may be configured to periodically and
+automatically run
+.B git fetch
+in the repositories your shell visits.  Opt in to this feature by providing
+.B \-\-fetch
+to the git\-sonar command line.
+
+.SH USAGE
+To use git\-sonar, you need to add it to your shell prompt.  This is done in
+different ways depending on your shell.
+.SS bash
+.nf
+# Add to .bashrc
+PS1="...\\$(git-sonar)..."
+.fi
+.SS zsh
+.nf
+# Add to .zshrc
+setopt PROMPT_SUBST
+export GIT_SONAR_COLOR_PREFIX='%{'
+export GIT_SONAR_COLOR_SUFFIX='%}'
+PROMPT='...$(git-sonar)...'
+.fi
+.SS fish
+.nf
+# Add to config.fish
+function fish_prompt
+    # ...
+    echo -n (git-sonar)
+    # ...
+end
+.fi
+.SS Ensuring prompt execution
+When setting the prompt variable, it is crucial that git\-sonar executes each
+time the prompt renders.  This way, the prompt will be able to react to changes
+in the repository.  Some details of the above snippets are necessary to ensure
+this happens:
+.P
+\- bash requires the use of double\-quotes around the value of
+.B $PS1.
+.br
+\- bash requires escaping the call to
+.B git\-sonar
+(add the backslash character).
+.br
+\- zsh requires the use of single\-quotes around the value of
+.B $PROMPT,
+as well as the use of
+.B PROMPT_SUBST.
+
+.SH PROMPT ELEMENTS
+All of the information output by the git\-sonar prompt is implemented by one of
+many prompt elements.  By default, each one is present in the rendered prompt,
+unless it has no information to report.  Each element is named in the form of
+.B %{element},
+as this is the syntax used by the prompt format customization string (see the
+"CONFIGURATION" section for more details).  Furthermore, most elements may be
+disabled by using a command\-line option (see "OPTIONS").
+
+.TP
+.B %{branch}
+Outputs the name of the checked\-out branch.  If
+.B HEAD
+is detached, outputs the abbreviated commit hash.
+
+.nf
+    git:(my-branch)
+    git:(detached@cb39e58e)
+.fi
+
+.TP
+.B %{status}
+Outputs a summary of
+.B git status \-\-porcelain,
+consisting of a count of changed files \- both by change type (addition,
+modification, deletion, etc.) as well as stage (changes staged in the index,
+unmerged, unstaged, or untracked files).
+
+Changes from the same stage are grouped together and color\-coded (see
+"CONFIGURATION" for setting colors).
+
+.nf
+    git:(my-branch) 1\m[green]\fBA\fR\m[] 2\m[red]\fBM\fR\m[]1\m[red]\fBD\fR\m[] 3?
+    git:(my-branch) 2\m[yellow]\fBU\fR\m[]1\m[yellow]\fBD\fR\m[]
+.fi
+
+The first example shows 1 new file staged for commit, 2 unstaged modifications,
+1 unstaged file deletion, as well as 3 untracked files which are unknown to the
+repository.
+
+The second example shows us in the middle of a failed merge, with 2 "both
+modified" unmerged files and 1 file "deleted by them/us".
+
+The change indicators displayed are the same ones used by
+.BR git\-status (1)
+in the
+.B \-\-short
+output format.
+
+.TP
+.B %{stash}
+If any stashed changes are saved, this element outputs the number of stashes
+available with a customizable icon.
+
+.nf
+    git:(my-branch) 2\m[yellow]\fB≡\fR\m[]
+.fi
+
+The example shows 2 stashed changes previously saved in this repository.
+
+.TP
+.B %{local}
+Outputs the number of commits that are different between
+.B HEAD
+and the configured upstream branch
+.B @{u},
+if present.  If there is no upstream branch, or the two are pointing to the
+same commit, nothing is output.
+
+.nf
+    git:(my-branch \m[green]\fB↑\fR\m[]5)
+    git:(my-branch 6\m[red]\fB↓\fR\m[])
+    git:(my-branch 6\m[yellow]\fB⇵\fR\m[]5)
+.fi
+
+In the three examples, the upstream branch is
+.B remotes/origin/my\-branch,
+and we are: ahead by 5 commits, behind by 6 commits, and diverged by 5/6 commits
+respectively.
+
+.TP
+.B %{remote}
+This element functions the same as the
+.B %{local}
+element, except that the upstream branch
+.B @{u}
+is compared to the repository's default branch.
+
+.nf
+    git:(\m[green]\fB↑\fR\m[]5 my-branch)
+    git:(6\m[red]\fB↓\fR\m[] my-branch)
+    git:(6\m[yellow]\fB⇵\fR\m[]5 my-branch)
+.fi
+
+In the three examples, the upstream branch is
+.B remotes/origin/my\-branch,
+the default remote branch is
+.B remotes/origin/master,
+and: my\-branch is ahead by 5 commits, master is ahead by 6 commits, and the two
+are diverged by 5/6 commits respectively.
+
+The default branch is determined automatically.
+
+.TP
+.B %{alert}
+Outputs a customizable icon whenever the repository is in the middle of an
+ongoing operation such as a merge, rebase, bisect, etc., or if the branch's
+configured upstream no longer exists.
+
+.nf
+    git:(\m[yellow]\fB⚡\fR\m[]detached@2fb1cc17)
+.fi
+
+The example shows us in the middle of a bisect session.  Since we are bisecting,
+.B HEAD
+is detached, with the next revision to test checked out.
+
+See also,
+.BR git\-precheck (1).
+
+.P
+Below is a more complete example, showcasing many elements of the prompt
+rendering at once in a fairly complex situation:
+
+.nf
+    o\-\-\-o\-\-\-o\-\-\-o\-\-\-o origin/master
+         \e
+          o\-\-\-o origin/my\-branch
+               \e
+                o\-\-\-o HEAD, my\-branch
+
+    git:(\m[yellow]\fB⚡\fR\m[]3\m[yellow]\fB⇵\fR\m[]2 my-branch \m[green]\fB↑\fR\m[]2) 1\m[yellow]\fB≡\fR\m[] 2\m[green]\fBM\fR\m[] 1\m[yellow]\fBU\fR\m[]
+.fi
+
+.B my\-branch
+is checked out, with the shown branch topology.  A merge from some other commit
+has started, but could not complete automatically.  Two files from the other
+side of the merge have no conflicts and are already staged, however 1 file is in
+conflict and must be resolved.  There is also 1 saved stash being shown.
+
+.SH OPTIONS
+.TP
+.B \-v, \-\-version
+Print the version of git\-sonar and exit.
+
+.TP
+.B \-h, \-\-help
+Display help for git\-sonar (opens this man page).
+
+.TP
+.B \-\-fetch
+git\-sonar will automatically fetch from remote repositories after a
+configurable amount of time passes.  A timestamp of the latest auto\-fetch is
+stored in the
+.B $GIT_DIR/lastupdatetime
+file.  The fetch operation is only triggered when the prompt renders, only runs
+in the repository your shell is in, and executes in the background.
+
+.P
+The remaining options affect the rendered prompt and are provided as a simple
+way to disable features without the need to use a custom prompt format string.
+For more powerful customization, see the "CONFIGURATION" section.
+
+.TP
+.B \-\-no\-remote\-commits
+Disable rendering the
+.B %{remote}
+prompt element, even if it is present in
+.B $GIT_SONAR_PROMPT_FORMAT.
+
+.TP
+.B \-\-no\-local\-commits
+Disable rendering the
+.B %{local}
+prompt element, even if it is present in
+.B $GIT_SONAR_PROMPT_FORMAT.
+
+.TP
+.B \-\-no\-status
+Disable rendering the
+.B %{status}
+prompt element, even if it is present in
+.B $GIT_SONAR_PROMPT_FORMAT.
+For simpler prompts, disabling this feature provides a decent speedup, but omits
+a lot of information.
+
+.TP
+.B \-\-no\-stash
+Disable rendering the
+.B %{stash}
+prompt element, even if it is present in
+.B $GIT_SONAR_PROMPT_FORMAT.
+
+.SH CONFIGURATION
+Colors are customized by using ANSI color codes with the environment variables
+listed below.  However, note that these escape sequences (and any unprintable
+characters used) need to be wrapped in markers that your shell uses to track the
+length of the prompt and handle line wrapping.  These markers will vary by shell
+and it is the responsibility of the user to insert the correct ones when
+exporting overrides for the variables below.  The default colors use markers
+that are compatible with bash.  Overrides for zsh can be seen in the "USAGE"
+section of this document.
+.P
+As a convention for this section, this syntax will be used to denote the use of
+a default color in another variable:
+
+.nf
+    ${<color\-name>} := [prefix marker] \\033[XXXm [suffix marker]
+.fi
+
+In cases where a default color is used, the markers remain configurable using
+a pair of variables below.
+.B XXX
+represents the color attributes required by
+.B <color\-name>.
+
+.TP
+.B $GIT_SONAR_COLOR_PREFIX
+The prefix escape code marker used by default colors.  User provided variables
+must insert their own markers and are unaffected by this value.
+
+Default:
+.B \\\001
+(bash compliant)
+
+.TP
+.B $GIT_SONAR_COLOR_SUFFIX
+The suffix escape code marker used by default colors.  User provided variables
+must insert their own markers are are unaffected by this value.
+
+Default:
+.B \\\002
+(bash compliant)
+
+.TP
+.B $GIT_SONAR_DEFAULT_COLOR
+The color which the terminal is reset to at the end of each prompt element.
+This variable is mainly useful for preserving a background color inside the
+git\-sonar prompt.
+
+Default:
+.B ${reset}
+(all terminal attributes cleared)
+
+.TP
+.B $GIT_SONAR_PROMPT_COLOR
+The text color used by the default prompt format string for the
+.B 'git:(' ')'
+characters surrounding the branch information.  If the user provides their own
+value for
+.B $GIT_SONAR_PROMPT_FORMAT,
+it is unaffected by this value.
+
+Default:
+.B ${bright black}
+
+.TP
+.B $GIT_SONAR_PROMPT_FORMAT
+When inside a git repository, this string controls the format of the output
+produced by git\-sonar.  It functions similarly as a printf\-style format
+string: most characters are output verbatim, and a format specifier syntax is
+used to substitute output from the prompt elements:
+
+.nf
+    %{element-name}
+.fi
+
+If
+.B element\-name
+is either prefixed or suffixed by a colon, the colon delimits a string that is
+affixed to the element output if and only if the element has any output to
+produce.  For example,
+.B %{[:stash:]}
+produces [1\m[yellow]\fB≡\fR\m[]] if a stash is available, but the extra
+brackets are omitted otherwise.  The default format string utilizes this to add
+optional spacing around elements which don't always appear active.
+
+See the "PROMPT ELEMENTS" section for a description of all possible outputs.
+
+.nf
+Default: (space) git:(%{alert}%{remote: }%{branch}%{ :local})%{ :stash}%{ :status}
+.fi
+
+.TP
+.B $GIT_SONAR_FETCH_TIME
+The number of seconds between automatic remote fetches when using
+.B \-\-fetch.
+
+Default:
+.B 300
+(5 minutes)
+
+.TP
+.B $GIT_SONAR_ALERT_ICON
+The symbol shown by the
+.B %{alert}
+prompt element.
+
+Default:
+.B ${yellow}⚡
+
+.TP
+.B $GIT_SONAR_STASH_ICON
+The symbol shown by the
+.B %{stash}
+prompt element.
+
+Default:
+.B ${yellow}≡
+
+.TP
+.B $GIT_SONAR_BRANCH_COLOR
+The text color used by the
+.B %{branch}
+prompt element when on a branch.
+
+Default:
+.B $GIT_SONAR_DEFAULT_COLOR
+
+.TP
+.B $GIT_SONAR_DETACHED_COLOR
+The text color used by the
+.B %{branch}
+prompt element when
+.B HEAD
+is detached.
+
+Default:
+.B $GIT_SONAR_DEFAULT_COLOR
+
+.TP
+.B $GIT_SONAR_STATUS_SEPARATOR
+The string used to separate the different change stages output by the
+.B %{status}
+prompt element.
+
+Default:
+.B (space)
+
+.TP
+.B $GIT_SONAR_AHEAD_ICON
+The symbol shown by the
+.B %{local}
+and
+.B %{remote}
+prompt elements when the primary ref is strictly ahead of the secondary.
+
+Default:
+.B ${green}↑
+
+.TP
+.B $GIT_SONAR_BEHIND_ICON
+The symbol shown by the
+.B %{local}
+and
+.B %{remote}
+prompt elements when the primary ref is strictly behind the secondary.
+
+Default:
+.B ${red}↓
+
+.TP
+.B $GIT_SONAR_DIVERGED_ICON
+The symbol shown by the
+.B %{local}
+and
+.B %{remote}
+prompt elements when the primary and secondary refs each hold unique commits.
+
+Default:
+.B ${yellow}⇵
+
+.TP
+.B $GIT_SONAR_STAGED_COLOR
+The text color used by the
+.B %{status}
+prompt element for change indicators of changes staged in the index.
+
+Default:
+.B ${green}
+
+.TP
+.B $GIT_SONAR_UNSTAGED_COLOR
+The text color used by the
+.B %{status}
+prompt element for change indicators of unstaged changes.
+
+Default:
+.B ${red}
+
+.TP
+.B $GIT_SONAR_UNMERGED_COLOR
+The text color used by the
+.B %{status}
+prompt element for change indicators of unmerged paths (conflicted files).
+
+Default:
+.B ${yellow}
+
+.TP
+.B $GIT_SONAR_UNTRACKED_COLOR
+The text color used by the
+.B %{status}
+prompt element for the untracked file indicator.
+
+Default:
+.B ${white}
+
+.SH SEE ALSO
+.BR git\-fetch (1),
+.BR git\-log (1),
+.BR git\-precheck (1),
+.BR git\-stash (1),
+.BR git\-status (1)
+
+.SH LICENSE
+.B git\-sonar
+is available under the terms of the
+.B MIT
+license.