Add maintenance message

app.py

@@ -83,6 +83,8 @@ st.set_page_config(layout="wide")
 st.title("RAFT: Real-world Annotated Few-shot Tasks")
 st.markdown(
     """
+⚠️ **The RAFT benchmark is currently undergoing maintenance and is not accepting submissions at the moment. We apologise for the inconvenience.**
+
 Large pre-trained language models have shown promise for few-shot learning, completing text-based tasks given only a few task-specific examples. Will models soon solve classification tasks that have so far been reserved for human research assistants? 
 
 [RAFT](https://raft.elicit.org) is a few-shot classification benchmark that tests language models: