updated leaderboard display

app.py

@@ -272,10 +272,10 @@ def display_leaderboard():
         try:
             users = load_users(USERS_JSON)
             # Convert the dataset to a pandas DataFrame
-            df_users = pd.DataFrame([{'user_name': key, 'points': value} for key, value in users.items()])
+            df_users = pd.DataFrame([{'User': key, 'Points': value} for key, value in users.items()])
 
             # Sort DataFrame by points in descending order
-            leaderboard = df_users.sort_values(by='points', ascending=False).reset_index(drop=True)
+            leaderboard = df_users.sort_values(by='Points', ascending=False).reset_index(drop=True)
             
             # Add a 'Rank' column starting from 1
             leaderboard['Rank'] = leaderboard.index + 1