[refactor] Move objets to separate files.

- ball
- bricks
- paddle
Update documentation and readme.
[fix] Game over: update player score.

paddle.py

@@ -0,0 +1,52 @@
+from screen import Screen, WHITE
+
+PADDLE_WIDTH = 70
+PADDLE_HEIGHT = 10
+PADDLE_COLOR = WHITE
+PADDLE_SPEED = 10
+
+
+class Paddle:
+    def __init__(self, screen: Screen):
+        """Initialize the paddle."""
+        self.screen_width = screen.width
+        self.screen_height = screen.height
+        self.x = (self.screen_width - PADDLE_WIDTH) // 2
+        self.y = self.screen_height - PADDLE_HEIGHT - 5
+        self.width = PADDLE_WIDTH
+        self.height = PADDLE_HEIGHT
+        self.speed = PADDLE_SPEED
+    
+    def move(self, direction: int):
+        """
+            Move paddle left or right.
+            Args: direction: -1 for left, 1 for right
+        """
+        self.x += self.speed * direction
+        if self.x < 0:
+            self.x = 0
+        elif self.x > self.screen_width - self.width:
+            self.x = self.screen_width - self.width
+    
+    def draw(self, screen: Screen):
+        """Draw paddle."""
+        screen.fbuf.fill_rect(self.x, self.y, self.width, self.height, PADDLE_COLOR)
+
+    def update(self, screen: Screen, joystick: Joystick):
+        """Update paddle position."""
+        if joystick.joy_left() == 0:
+            self.move(-1)
+        elif joystick.joy_right() == 0:
+            self.move(1)
+        self.draw(screen)
+
+    def hit(self, ball: Ball) -> bool:
+        """Check if the ball hits the paddle and adjust its position."""
+        if (
+            self.x <= ball.x <= self.x + self.width 
+            and self.y <= ball.y + ball.radius <= self.y + self.height
+        ):
+            # Adjust the ball's position to be just above the paddle
+            ball.y = self.y - ball.radius - 2
+            return True
+        return False