SubmittingPatches: demonstrate using git-contacts with git-send-email

Signed-off-by: Linus Arver <linusa@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: Linus Arver

Documentation/SubmittingPatches

@@ -417,6 +417,13 @@ trial merges of your topic to `next` and `seen`, you may have noticed
 work by others conflicting with your changes.  There is a good possibility
 that these people may know the area you are touching well.
 
+If you are using `send-email`, you can feed it the output of `git-contacts` like
+this:
+
+....
+	git send-email --cc-cmd='perl contrib/contacts/git-contacts' feature/*.patch
+....
+
 :current-maintainer: footnote:[The current maintainer: gitster@pobox.com]
 :git-ml: footnote:[The mailing list: git@vger.kernel.org]