feat: implement gravity on current piece

entity/Entity.py

@@ -8,9 +8,10 @@ class Entity:
         self.points = points
         self.color = color
         self.border_color = border_color
+        self.elapsed_time = 0
 
-    def update(self) -> None:
-        pass
+    def update(self, elapsed_time) -> None:
+        self.elapsed_time += elapsed_time
 
     def draw(self, surface: pygame.Surface) -> None:
         tile_size = ConfigurationManager.configuration["engine"]["tile-size"]
@@ -20,7 +21,7 @@ class Entity:
             if self.border_color:
                 pygame.draw.polygon(surface, pygame.Color(self.border_color), square, max(tile_size // 6, 1))
 
-    def collide(self, entity) -> bool:
+    def collide(self, entity) -> bool: # TODO figure out how to do type hint for entity param of type Entity
         for square_one in self.points:
             for square_two in entity.points:
                 for i in range(4): # 4 vertices