merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/Documentation/git-shortlog.txt

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+git-shortlog(1)
+===============
+
+NAME
+----
+git-shortlog - Summarize 'git log' output
+
+SYNOPSIS
+--------
+[verse]
+'git shortlog' [<options>] [<revision range>] [[--] <path>...]
+git log --pretty=short | 'git shortlog' [<options>]
+
+DESCRIPTION
+-----------
+Summarizes 'git log' output in a format suitable for inclusion
+in release announcements. Each commit will be grouped by author and title.
+
+Additionally, "[PATCH]" will be stripped from the commit description.
+
+If no revisions are passed on the command line and either standard input
+is not a terminal or there is no current branch, 'git shortlog' will
+output a summary of the log read from standard input, without
+reference to the current repository.
+
+OPTIONS
+-------
+
+-n::
+--numbered::
+	Sort output according to the number of commits per author instead
+	of author alphabetic order.
+
+-s::
+--summary::
+	Suppress commit description and provide a commit count summary only.
+
+-e::
+--email::
+	Show the email address of each author.
+
+--format[=<format>]::
+	Instead of the commit subject, use some other information to
+	describe each commit.  '<format>' can be any string accepted
+	by the `--format` option of 'git log', such as '* [%h] %s'.
+	(See the "PRETTY FORMATS" section of linkgit:git-log[1].)
+
+	Each pretty-printed commit will be rewrapped before it is shown.
+
+-c::
+--committer::
+	Collect and show committer identities instead of authors.
+
+-w[<width>[,<indent1>[,<indent2>]]]::
+	Linewrap the output by wrapping each line at `width`.  The first
+	line of each entry is indented by `indent1` spaces, and the second
+	and subsequent lines are indented by `indent2` spaces. `width`,
+	`indent1`, and `indent2` default to 76, 6 and 9 respectively.
++
+If width is `0` (zero) then indent the lines of the output without wrapping
+them.
+
+<revision range>::
+	Show only commits in the specified revision range.  When no
+	<revision range> is specified, it defaults to `HEAD` (i.e. the
+	whole history leading to the current commit).  `origin..HEAD`
+	specifies all the commits reachable from the current commit
+	(i.e. `HEAD`), but not from `origin`. For a complete list of
+	ways to spell <revision range>, see the "Specifying Ranges"
+	section of linkgit:gitrevisions[7].
+
+[--] <path>...::
+	Consider only commits that are enough to explain how the files
+	that match the specified paths came to be.
++
+Paths may need to be prefixed with `--` to separate them from
+options or the revision range, when confusion arises.
+
+MAPPING AUTHORS
+---------------
+
+The `.mailmap` feature is used to coalesce together commits by the same
+person in the shortlog, where their name and/or email address was
+spelled differently.
+
+include::mailmap.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite