Armatures on github pages

This commit adds a rake task that builds a gh-pages branch ready
to be published on github-pages.

Signed-off-by: brice <brice@daysofwonder.com>
More jekyll armature website

* generates the gh-page commit automatically
* better index page

Signed-off-by: brice <brice@daysofwonder.com>
Armature website

* fix where the file ends in the gh-pages
* make sure we rewrite internal links to the .html file

Signed-off-by: brice <brice@daysofwonder.com>