push: mention --verbose option in documentation

Before this commit, only '-v' was documented.
Signed-off-by: NSteffen Prohaska <prohaska@zib.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/git-push.txt

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git-push' [--all] [--dry-run] [--tags] [--receive-pack=<git-receive-pack>]
-           [--repo=all] [-f | --force] [-v] [<repository> <refspec>...]
+           [--repo=all] [-f | --force] [-v | --verbose] [<repository> <refspec>...]
 
 DESCRIPTION
 -----------
@@ -95,7 +95,7 @@ the remote repository.
 	transfer spends extra cycles to minimize the number of
 	objects to be sent and meant to be used on slower connection.
 
--v::
+-v, \--verbose::
 	Run verbosely.
 
 include::urls-remotes.txt[]