Update app.py

app.py

@@ -3,7 +3,7 @@ from typing import List
 
 from langchain.embeddings.openai import OpenAIEmbeddings
 from langchain.text_splitter import RecursiveCharacterTextSplitter
-from langchain.vectorstores import Chroma
+from langchain_community.vectorstores import Chroma
 from langchain.chains import (
     ConversationalRetrievalChain,
 )