bug#1571: only one word about git in (info "(emacs)Version Control")

In (info "(emacs)Version Control") there is literally only one word
about git, on (info "(emacs)Customizing VC"). Somebody who has used
git for more than a few minutes should add something.
emacs-version "22.2.1"
(I added X-Debbugs-CC: git@vger.kernel.org (lest I use a real CC
causing bug number escalation), but it seems the git list filters
things coming in from the side.)