Send commits to mailing list(s)

The browser folks wants us to enable commit emails from fenix and other TB related repositories to their commit mailing list. We should find a way to do this in a structured way for the tpo/ namespace such that all our projects (also upcoming) gets these hooks enabled.

For now, we need to get Fenix and Tor-Browser.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information