Add GitLab Duo Chat into the handbook for conversational help

Problem to solve

The handbook search requires contextual search keywords, and does not always immediately bring up the required answers.

A conversational chat can help everyone to ask questions with additional context, and follow-up questions.

Proposal

Add the GitLab Duo Chat prompt into the handbook views.

Use an approach similar to the GitLab documentation, with RAG = Retrieval Augmented Generation, to avoid retraining models where the content frequently changes.

@tlinz

Means we use embeddings to find snippets in the handbook, that relate to the users questions and then send those together with the user question to the LLM to generate an answer.

@marshall007

making AI Agents chat embed-able in other applications (including static sites like handbook) is in the backlog:  gitlab-org&12330 (closed)

Tasks

• PoC with local LLMs and vector database, RAG
  • Explore if the many handbook pages pose a performance problem.
  • Explore fine-tuning etc.
• Follow GitLab RAG capabilities
  • Custom data source (RAG embeddings) on GitLab.com and only for team members? -- needs infrastructure decisions after product support
  • Explore AI agents integrations
• How to embed the GitLab UI with Duo Chat into a Hugo handbook theme, i.e. as side overlay?
  • Separate technologies - gitlab-ui and chat is Typescript/VueJS, Hugo is Go/Javascript.

Resources

1. RAG: gitlab-org/gitlab#454462
   1. https://www.promptingguide.ai/research/rag
      1. 

/cc @cynthia @erran