This is a way to turn any pubkey into a customizable group chat and community. You choose the relay where it's hosted and the relay handles moderation (can be whatever you want). You also get to select which content types appear in each tab and soon you'll be able to also share existing publications to the group. I haven't implemented yet but yes you'll be able to use an existing NIP-29 group as a communikey (I'll do this with the chachi group).