Added coin

Coin/Coin.gd

@@ -0,0 +1,22 @@
+extends RigidBody2D
+
+class_name Coin
+
+signal coin_collected()
+
+func _ready() -> void:
+	linear_velocity = Vector2(0, 40)
+
+func set_upgrade(_chr : String, color : Color) -> void:
+	$Polygon2D.color = color
+	
+func _on_body_entered(body: Node) -> void:
+	if body is Floor:
+		get_parent().call_deferred("remove_child", self)
+		call_deferred("queue_free")
+		return
+	if body is Paddle:
+		coin_collected.emit()
+		get_parent().call_deferred("remove_child", self)
+		call_deferred("queue_free")
+