BM25 hybrid RAG

[MrCsabaToth]

I knew about hybrid retrieval. Recently I've heard BM25 mentioned a lot, let's try to use that. The question is how well ObjectBox will support that.

[MrCsabaToth]

Reading:

• https://en.wikipedia.org/wiki/Okapi_BM25
• https://docs.llamaindex.ai/en/stable/examples/retrievers/bm25_retriever/