git-show-branch doc: show -g as synonym to --reflog in the list

Signed-off-by: jidanni <jidanni@jidanni.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-show-branch.txt

@@ -99,12 +99,12 @@ OPTIONS
 	will show the revisions given by "git rev-list {caret}master
 	topic1 topic2"
 
+-g::
 --reflog[=<n>[,<base>]] [<ref>]::
 	Shows <n> most recent ref-log entries for the given
 	ref.  If <base> is given, <n> entries going back from
 	that entry.  <base> can be specified as count or date.
-	`-g` can be used as a short-hand for this option.  When
+	When no explicit <ref> parameter is given, it defaults to the
-	no explicit <ref> parameter is given, it defaults to the
 	current branch (or `HEAD` if it is detached).
 
 Note that --more, --list, --independent and --merge-base options