doc/clone: update caption for GIT URLS cross-reference

The description of the <repository> argument directs readers to "See the
URLS section below".  When generating HTML this becomes a link to the
"GIT URLS" section.  When reading the man page in a terminal, the
caption is slightly misleading.  Use "GIT URLS" as the caption to avoid
any confusion.

Signed-off-by: Todd Zullinger <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: tmzullinger

Documentation/git-clone.txt

@@ -260,7 +260,7 @@ or `--mirror` is given)
 
 <repository>::
 	The (possibly remote) repository to clone from.  See the
-	<<URLS,URLS>> section below for more information on specifying
+	<<URLS,GIT URLS>> section below for more information on specifying
 	repositories.
 
 <directory>::