Feature request: Message relay
Especially small servers suffer the problem that they don't have much public content. For Diaspora this problem was solved with the so called "social relay". Every participating server sends the whole public content of their users additionally to a relay server that distributes it to the other servers.
To limit the amount of messages, servers can subscribe either to all the content or only to selected tags. See for example the list of one of my servers: https://squeet.me/.well-known/x-social-relay
It would be great if Pleroma could do something similar. Possibly using the same endpoints, but using AP as a protocol.