Sqlite + Sqlite VSS Adapter

[lalalune]

Right now we are tied to Supabase. We want a local build option that isn't so tied into it

• [x] Abstract Supabase adapter
• [x] Add a sqlite db adapter
• [x] Add docs for quickstart locally
• [x] Make developer experience for getting started ideal with sqlite, i.e. no db setup at all

Kinda needs this: https://github.com/JoinTheAlliance/bgent/issues/4