NodeBB-ActivityPub Bridge Test Instance

@trwnh @mat @mcc @alter_kaker @esoteric_programmer Yeah, my understanding a while back was that the canonical location is defined by reference to the DID address. The way, you can still have a canonical address even if the originating account shifts to a new address. That prevents the old PDS from retaining authority. But so much has changed since I firmed that understanding that I wasn't sure whether or not it had changed. (One would hope the procedures for determining canonicity wouldn't change.)