Update rankings message in leaderboards tab

The code now adds a placeholder message about launching the leaderboards once enough votes have been gathered for the guardrails feature. This message replaces the previously empty leaderboard section. The original line to get rankings has been commented out for future use.

app.py

@@ -451,8 +451,8 @@ with gr.Blocks(
 
     with gr.Tab(label="🏆 Leaderboard", elem_id="leaderboard") as leaderboard_tab:
         gr.Markdown("## 🏆 Guardrails Leaderboard")
-        rankings = gr.Markdown("")
-        leaderboard_tab.select(get_rankings, None, [rankings])
+        rankings = gr.Markdown("We will launch the guardrails leaderboard once enough votes are collected. Ranking will be calculated based on ELO ratings. Keep playing so that we can collect enough data.")
+        # leaderboard_tab.select(get_rankings, None, [rankings])
 
     gr.Markdown(
         """