Profile customization

By default the profile page of a user is the list of repositories they own. It is possible to customize it with a short description that shows to the left, under their avatar. It can now be fully personalized with a markdown file that is displayed instead of the list of repositories.

It uses the README.md file from the .profile repository of the user, if it exists.

NOTE: if a the .profile repository is private the README.md they contain will be displayed publicly. It is strongly recommended to verify no such repository exist in a given instance before upgrading.