Update app.py

app.py

@@ -11,7 +11,7 @@ from langchain.memory import ConversationBufferMemory
 from langchain.chains import ConversationalRetrievalChain
 from langchain.llms import HuggingFaceHub
 
-from htmlTemplates import css, bot_template, user_template
+from typing import Union
 
 from dotenv import load_dotenv
 from PyPDF2 import PdfReader