Rename the submission date column from Release to Submitted

server.py

@@ -731,7 +731,7 @@ class LeaderboardServer:
                 
                 extra_attributes_map_word_to_header = {
                     "model": "Model",
-                    "release": "Release",
+                    "release": "Submitted",
                     "average_score": "Average ⬆️",
                     "team_name": "Team name",
                     "model_name": "Model name",