On top of the NIP-34 issue spec, ngit and gitworkshop currently support these three extra features: 1) post issue creation labels/tags, 2) editable issue subjects and 3) CoverNotes - editable pinned note with version history designed similar to an editable issue description. Here is the spec I am using:

gitworkshop - Decentralized Git

Decentralized GitHub alternative over Nostr