Update README.md

corrected a mistake

Author: MXD-K1

README.md

@@ -114,7 +114,7 @@ Example task record:
   "id": 1,
   "description": "Buy groceries",
   "status": "todo",
-  "createdAt": "07-04-2025 15:19:48"",
+  "createdAt": "07-04-2025 15:19:48",
   "updatedAt": "07-04-2025 15:19:48"
 }
 ```