docs: `/reference` sidebar improvements (#6115)
* wip
* 🤖 lazy commit
* 🤖 lazy commit
* revert some changes, remove prettier jsdoc plugin for now
* sidebar tweaks
* add adapter module docs
* remove provider docs
* embed all reflections under modules
Based on: https://github.com/TypeStrong/typedoc/issues/2006
Related: https://github.com/tgreyuk/typedoc-plugin-markdown/issues/338
* no trailing slash, update theme
* updates
* update snapshot
* update sidebar and overview
