fix(docs-site): update generation scripts for canonical content location

Update generate-docs.mjs and generate-llms.mjs to work with the new
canonical documentation location at docs-site/src/content/docs/.

- generate-docs.mjs: Simplified to no-op since docs are now authored
  directly in the Starlight content collection
- generate-llms.mjs: Updated to read from src/content/docs/ instead of
  the non-existent ../docs/ directory
- Regenerate public assets with correct paths

Author: MasuRii