Add comments in UiElement.py

src/ui/UiElement.py

@@ -2,6 +2,12 @@ import pygame
 
 
 class UiElement(pygame.sprite.Sprite):
-    def __init__(self, rect):
+    rect: pygame.Rect
+
+    def __init__(self, rect: pygame.Rect):
+        """
+        Creates UiElement object.
+        :param rect: UiElement will be drawn on this rectangle.
+        """
         super().__init__()
         self.rect = rect