Doc landing page still on 2.2

[Eric Siegerman]

I just noticed that the documentation landing page,
http://doc.bazaar.canonical.com/en/,
hasn't been updated to reflect the release of 2.3.

This is true for all of en, fr, ja, ru.

(BTW, I wonder whether it's actually good to have a French
landing page when it points to English docs.  Seems to me a
francophone reader might feel that page to be a bit of a
bait-and-switch.)

  - Eric