implemented init and add_player

.gitignore

+.idea
+__pycache__

leaderboard.py

+from datetime import datetime,timedelta
+
+def init_leaderboard()->dict[str,timedelta]:
+    return {}
+
+
+def add_player(leaderboard:dict[str,timedelta],player_name:str)->bool:
+    if player_name in leaderboard:
+        return False
+    leaderboard.update({player_name:None})
+    return True