添加雨滴特效，已有基本效果，待完善

src/scenes/base_scene.py

@@ -1,8 +1,9 @@
 import pygame
 
 class BaseScene:
-    def __init__(self, screen: pygame.Surface):
+    def __init__(self, screen: pygame.Surface, clock: pygame.time.Clock):
         self.screen = screen
+        self.clock = clock
         self.next_scene = None
 
     def update(self):