Update app.py

app.py

@@ -2,6 +2,8 @@ import os
 import threading
 from flask import Flask, render_template, request, jsonify
 from rss_processor import fetch_rss_feeds, process_and_store_articles, vector_db, download_from_hf_hub, upload_to_hf_hub, clean_text
+from langchain.vectorstores import Chroma
+
 import logging
 import time
 from datetime import datetime