Monero needs an MIME type

Lots of people are doing their own monero integrations in forked clients and I tought making a clear base to develop on would be better.

Basically, MIME types is the thing for example behind recognizing a magnet URL for torrenting on a browser (when Firefox asks you to open your torrent client for example).

With a MIME type, the hyperlinking feature (already existing on Monero) could be used on, and improved with more features like asking to sign a message for authenticating somewhere.