Documentation: note about contrib/.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/SubmittingPatches

@@ -101,6 +101,11 @@ send it "To:" the mailing list, and optionally "cc:" him.  If it
 is trivially correct or after the list reached a consensus, send
 it "To:" the maintainer and optionally "cc:" the list.
 
+Also note that your maintainer does not actively involve himself in
+maintaining what are in contrib/ hierarchy.  When you send fixes and
+enhancements to them, do not forget to "cc: " the person who primarily
+worked on that hierarchy in contrib/.
+
 
 (6) Sign your work