Cleaned up window base code

Assets/Scripts/WindowBase.cs

@@ -54,6 +54,13 @@ namespace InterfaceOff
         }
 
         public virtual void OnWindowInstantiation() { }
-        public virtual void OnWindowClicked() { }
+        
+        /* Default close button closes the window */
+        public virtual void OnWindowCloseButtonClicked() => DestroyWindow();
+
+        protected void DestroyWindow()
+        {
+            Destroy(gameObject);
+        }
     }
 }