Adopt existing git directories

If directories containing bare git repositories exist in the
[repository].ROOT hierarchy, they can be imported using the admin
panel.
Make sure the directory names are lowercase.
[repository].ROOT/{user,org}/{repo}.git will become a project owned by the user or the org.
Go to 
/admin/repos/unadopted
In trusted environments, users can also be given similar permissions via the 
ALLOW_ADOPTION_OF_UNADOPTED_REPOSITORIES setting.