generate config docs from zod metadata

[claytercek]

Right now we have the types/descriptions/defaults available in the zod schemas, but we're just copy and pasting that info to the docs. We should be able to generate directly from the zod schemas.

This might be tough to do at build-time with vitepress. We don't want to create data routes for EVERY config. Maybe we can borrow some logic from how we're getting the version numbers currently with package-versions.data.ts?