Add support for Postgate and Threadgate records in ATProtoBluesky.

Further DocC cleanup.

Move pdsURL from non-authentication and authentication-optional methods into an argument within the ATProtoKit and ATProtoAdmin initializers.

Moved pdsURL from non-authentication and authentication optional methods into an argument within the ATProtoKit and ATProtoAdmin classes.

• This is to simply make things cleaner, as well as to give the lexicon generator less of a burden to deal with.