game: add enemy on-hit animation

scenes/enemies/enemy.gd

@@ -42,6 +42,7 @@ func take_damage(value: float, is_crit: bool = false):
 	var dm = preload("res://scenes/damage_numbers.tscn").instantiate()
 	dm.damage_taken = value
 	dm.critical_damage = is_crit
+	animation_player.play("take_damage")
 	add_child(dm)
 	if health <= 0:
 		die()