add "unique = true" clause to games showcase model

Author: KushPatel-18

server/game_dev/models.py

@@ -69,7 +69,7 @@ def __str__(self):
 
 
 class GameShowcase(models.Model):
-    game = models.ForeignKey('Game', on_delete=models.CASCADE, related_name='game_showcases')
+    game = models.ForeignKey('Game', on_delete=models.CASCADE, related_name='game_showcases', unique=True)
     description = models.TextField()
 
     def __str__(self):