refactor out a get_welcome_message() stub

mind_palace/app.py

@@ -16,12 +16,6 @@
     st.text("Coming soon...")
 
 
-if "messages" not in st.session_state.keys():  # Initialize the chat messages history
-    st.session_state.messages = [
-        {"role": "assistant", "content": "Ask me a question about these PDFs"}
-    ]
-
-
 @st.cache_resource(show_spinner=False)
 def load_index(model):
     with st.spinner(
@@ -35,6 +29,17 @@ def load_index(model):
 vector_index = load_index(gpt_model)
 query_engine = CitationQueryEngine.from_args(index=vector_index, verbose=True)
 
+
+def get_welcome_message():
+    return "Ask me a question about these PDFs"
+
+
+if "messages" not in st.session_state.keys():  # Initialize the chat messages history
+    st.session_state.messages = [
+        {"role": "assistant", "content": get_welcome_message()}
+    ]
+
+
 if prompt := st.chat_input(
     "Your question"
 ):  # Prompt for user input and save to chat history