ls-remote: document --refs option

The --refs option was originally introduced in 2718ff0 ("Improve
git-peek-remote").  The ls-remote command was first documented in
972b6fe ("ls-remote: drop storing operation and add documentation."),
but the --refs option was never documented.  Fix this.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-ls-remote.txt

@@ -9,7 +9,7 @@ git-ls-remote - List references in a remote repository
 SYNOPSIS
 --------
 [verse]
-'git ls-remote' [--heads] [--tags]  [--upload-pack=<exec>]
+'git ls-remote' [--heads] [--tags] [--refs] [--upload-pack=<exec>]
 	      [-q | --quiet] [--exit-code] <repository> [<refs>...]
 
 DESCRIPTION
@@ -29,6 +29,9 @@ OPTIONS
 	both, references stored in refs/heads and refs/tags are
 	displayed.
 
+--refs::
+	Do not show peeled tags or pseudorefs like HEAD	in the output.
+
 -q::
 --quiet::
 	Do not print remote URL to stderr.

builtin/ls-remote.c

@@ -4,7 +4,7 @@
 #include "remote.h"
 
 static const char ls_remote_usage[] =
-"git ls-remote [--heads] [--tags]  [--upload-pack=<exec>]\n"
+"git ls-remote [--heads] [--tags] [--refs] [--upload-pack=<exec>]\n"
 "                     [-q | --quiet] [--exit-code] [--get-url] [<repository> [<refs>...]]";
 
 /*