Update app.py

temporary fix for the exception

app.py

@@ -146,7 +146,7 @@ def main():
     )
 
     st.markdown("# Chat with a Bot")
-    st.markdown("This bot tries to answer questions about multiple PDFs.")
+    st.markdown("This bot tries to answer questions about multiple PDFs. Let the processing of the PDF finish before adding your question. 🙏🏾")
 
     st.write(css, unsafe_allow_html=True)