Yet another FEP-ef61 update: https://codeberg.org/fediverse/fep/pulls/275/files

I added some notes on backward compatibility (DID URLs vs HTTPS URLs vs url property) and location discovery (aliases vs sameAs vs alsoKnownAs vs url).

Verification process was clarified too. In FEP-ef61 world all you need to do is verify the signature. Fragile same-origin checks are no longer necessary.