update warning msg

app.py

@@ -98,4 +98,5 @@ if st.session_state.thread_id:
                 with st.chat_message("assistant"):
                     st.markdown(message.content[0].text.value)
 else:
-    st.write("Click on 'Start Chat' to start a new thread.")
+    st.write("\n")
+    st.info("Click on 'Start Chat' to start/continue a thread.", icon='⚠')