[Vala] [Wikibooks] Cover Page

[Luca Dionisi <luca dionisi gmail com>]

I've created a cover page for the book
http://en.wikibooks.org/wiki/Vala_Programming/Cover

There's a list of contributors. So, if you contribute you are invited
to enlist yourself.

There's also a link to a page used for discussions on the book as a
whole. Anyway I suggest to use also this mailing list for important
discussions, to be sure that anyone interested in the project can see
and participate.

--Luca