To make updating the notmuchmail.org wiki 'news' section more
straightforward the content of the NEWS file has now been brought
to almost the same as the *.mdwn files in the wiki page.
The changes are basically insertion of mdwn formatting "commands".
More effort has been put into formatting the newer release entries
(0.12, 0.11 & 0.10) than older. Commit to format 0.13 entries will
be made available separately.