Add ownership of the git configuration file

[ekohl]

This allows users to run git config commands without having to set up permissions. The config file is marked as noreplace to respect the user's content.

A %ghost may also work, but I'm not sure.

This came up in https://github.com/theforeman/foreman-documentation/pull/3243 and I think this can simplify the procedure for users.

[ekohl]

If/When this is merged, we should submit a docs update to simplify the procedure.