Merge pull request #32 from jsilvestre/master

Fixed: wrong link in homepage. Close #31
new home page
add social content
add new images
fix responsive
fix install link
fix menu
make 2000 app downloaded bigger
fix tagline
Merge branch 'master' of github.com:mycozycloud/cozy-docs

Conflicts:
	package.json
	src/layouts/homepage.html.jade
little style and text improvments
Fixed: typos (thank you Harlan)