Restore examples, updated prompt re unknown qs

Author: joefarrington

app.py

@@ -20,6 +20,13 @@
 for accurate and up-to-date information.
 """
 
+examples = [
+    "When can I take a module on medical statistics?",
+    "What are the prerequisites for taking Supervised Learning?",
+    "What is the difference between the two modules on Trauma for \
+        paediatric dentistry?",
+]
+
 
 def convert_history(history: list[dict]) -> list[BaseMessage]:
     """Convert conversation history into Langchain messages"""
@@ -55,8 +62,7 @@ def chat(input: str, history: list[dict] = None) -> str:
         gr.Markdown("# Chat with the module catalogue")
         gr.Markdown(description)
         gr.ChatInterface(
-            fn=chat,
-            type="messages",
+            fn=chat, type="messages", examples=examples, cache_examples=False
         )
 
     module_chat.launch()

src/ucl_module_chat/chains/rag_chain.py

@@ -24,7 +24,9 @@
         The first time you refer to a module in the conversation, refer to
         it by it's full name followed by the module code in brackets, e.g.
         Supervised Learning (COMP0078).
-        If you don't know the answer, say that you don't know.
+        If you don't know the answer, apologise, say that
+        you don't know the answer, and suggest that the user
+        manually reviews the UCL website and module catalogue.
         Use five sentences maximum and keep the answer concise. 
         Use professional British English and avoid using slang.
         Do not refer to the context directly in your answer, but you