Add trunk abstract/keyword for more accurate recall result

[travisgu]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

Suggest to add a feature for more accurate RAG result:

1. use LLM to extract key word and generate a short abstract for each trunk;
2. enhance the search to allow keyword and abstract search;
3. In hybrid search mode, the keyword is extracted from the question and used to match the trunk keyword and abstract,

This can make the recall result more better.

2. Additional context or comments

No response

3. Can you help us with this feature?

• I am interested in contributing to this feature.