manpages: italicize git command names (which were in teletype font)

The names of git commands are not meant to be entered at the
commandline; they are just names. So we render them in italics,
as is usual for command names in manpages.

Using

	doit () {
	  perl -e 'for (<>) { s/\`(git-[^\`.]*)\`/'\''\1'\''/g; print }'
	}
	for i in git*.txt config.txt diff*.txt blame*.txt fetch*.txt i18n.txt \
	        merge*.txt pretty*.txt pull*.txt rev*.txt urls*.txt
	do
	  doit <"$i" >"$i+" && mv "$i+" "$i"
	done
	git diff

.

Signed-off-by: Jonathan Nieder <jrnieder@uchicago.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git-instaweb.txt b/Documentation/git-instaweb.txt
index e7ca537..22da21a 100644
--- a/Documentation/git-instaweb.txt
+++ b/Documentation/git-instaweb.txt
@@ -44,7 +44,7 @@
 -b::
 --browser::
 	The web browser that should be used to view the gitweb
-	page. This will be passed to the `git-web--browse` helper
+	page. This will be passed to the 'git-web--browse' helper
 	script along with the URL of the gitweb instance. See
 	linkgit:git-web--browse[1] for more information about this. If
 	the script fails, the URL will be printed to stdout.