README: update stale and/or incorrect information

Ramkumar Ramachandra noticed that the old address for the marc
archive no longer works.  Update it to its marc.info address,
and also refer to the gmane site.

Remove the reference to "note from the maintainer", which is not
usually followed by any useful discussion on status, direction nor
tasks.

Also replace the reference to "What's in git.git" with "What's
cooking".

Signed-off-by: Junio C Hamano <gitster@pobox.com>

README

@@ -47,11 +47,10 @@ requests, comments and patches to git@vger.kernel.org (read
 Documentation/SubmittingPatches for instructions on patch submission).
 To subscribe to the list, send an email with just "subscribe git" in
 the body to majordomo@vger.kernel.org. The mailing list archives are
-available at http://marc.theaimsgroup.com/?l=git and other archival
-sites.
+available at http://news.gmane.org/gmane.comp.version-control.git/,
+http://marc.info/?l=git and other archival sites.
 
-The messages titled "A note from the maintainer", "What's in
-git.git (stable)" and "What's cooking in git.git (topics)" and
-the discussion following them on the mailing list give a good
-reference for project status, development direction and
-remaining tasks.
+The maintainer frequently sends the "What's cooking" reports that
+list the current status of various development topics to the mailing
+list.  The discussion following them give a good reference for
+project status, development direction and remaining tasks.