feat: 1. replace black with ruff for fomatting and sort import (#489)

2. use tavily from`langchain-tavily` rather than the older one from `langchain-community`

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

src/rag/ragflow.py

@@ -2,11 +2,13 @@
 # SPDX-License-Identifier: MIT
 
 import os
-import requests
-from src.rag.retriever import Chunk, Document, Resource, Retriever
 from typing import List, Optional
 from urllib.parse import urlparse
 
+import requests
+
+from src.rag.retriever import Chunk, Document, Resource, Retriever
+
 
 class RAGFlowProvider(Retriever):
     """