chore(docs): initial commit

[psteinroe]

adds initial docs with generated documentation wherever possible.

• codegen for default config
• codegen for env vars
• codegen for cli reference
• codegen for lint rules
• codegen for config schema, but I think we dont use schemars everywhere already. I checked and it's possible to use json schemas for toml files so we should at least add it at some point. (done in feat(docs): generate json schema for config #206)
• Integrate docs codegen in CI

also renamed a few leftovers to PGLT

Next, we need to focus on the specific use cases and provide guides for them, especially "lint your migration files".

[juleswritescode]

Looks great to me :)