(EAI-156): `mongodb-chatbot-server` docs + generated reference docs + ingest/optimize rename

[mongodben]

Jira:

• https://jira.mongodb.org/browse/EAI-156
• https://jira.mongodb.org/browse/EAI-172

Changes

• Docs for mongodb-chat-server. include pages for:
  • [x] configure
  • [x] conversations
  • [x] evaluate
  • [x] custom logic
  • [x] llm
  • [x] preprocess
  • [x] persist
  • [x] retrieve
  • [x] references
• [x] Generated reference docs
• [x] Update TSDoc comments to be compatible with generated reference docs
• [x] Add reference docs links to ingest docs
• [x] Rename 'ingest/fine-tune' page to "ingest/optimize" to make clear that not LLM-based fine tuning

Notes

• generated reference docs not included in the PR (.gitignored). you can see them by pulling down the PR and running npm start in the docs package.