Add .DS_Store to gitignore and document hybrid search in README

Author: ToastCoder

.gitignore

@@ -206,6 +206,9 @@ marimo/_static/
 marimo/_lsp/
 __marimo__/
 
+# macOS
+.DS_Store
+
 # VSCode
 .vscode/
 mongo_data/

README.md

@@ -33,9 +33,24 @@ This script will handle all the setup of Ollama Package and the model and as wel
 * **AI/LLM:** Ollama (Llama 3.2 3B)
 * **Embeddings:** Nomic Embed Text
 * **Vector Store:** ChromaDB
+* **Retrieval:** Hybrid search (semantic + BM25 keyword)
 * **Database:** MongoDB (for user authentication and chat history)
 * **Orchestration:** Langchain & Docker
 
+## Search Configuration
+
+The app uses **hybrid search** combining semantic (vector) and keyword (BM25) retrieval:
+
+| Parameter         | Default | Description                                        |
+|-------------------|---------|----------------------------------------------------|
+| `enabled`         | `true`  | Toggle hybrid search on/off                        |
+| `semantic_weight` | `0.7`   | Weight for semantic (embedding) similarity scores  |
+| `bm25_weight`     | `0.3`   | Weight for BM25 keyword matching scores            |
+| `top_k`           | `6`     | Number of final documents returned to the LLM      |
+| `fetch_k`         | `18`    | Documents fetched per retriever before fusion      |
+
+Disable hybrid search (`"enabled": false`) to fall back to semantic-only retrieval.
+
 ## Customizing the HR Policy
 
 By default, the application uses the provided 2016 HR Manual. To use your own data: