FEP-ef61 update: https://codeberg.org/fediverse/fep/pulls/308

Further simplifying the spec by replacing aliases property with gateway (or should it be gateways?). The first gateway in the list is used to create MastoPub compatible URLs.

Gateways will probably be used to retrieve media as well:

https://social.example/.well-known/apgateway/urn:sha256:11a8c27212f7bbc47a952494581f3bc92e84883ac343cd11a1e4f8eaa1254f4b

#fep_ef61