add enemy hitbox and refactor to characterBody2d

scenes/hit_box.tscn

@@ -0,0 +1,14 @@
+[gd_scene load_steps=3 format=3 uid="uid://bmv6eq8rt7fsb"]
+
+[ext_resource type="Script" uid="uid://b3mc3t5k3yr7y" path="res://hit_box.gd" id="1_o631b"]
+[ext_resource type="AudioStream" uid="uid://bhayvfhydadqy" path="res://assets/sounds/tap.wav" id="2_d7xod"]
+
+[node name="HitBox" type="Area2D"]
+collision_mask = 2
+script = ExtResource("1_o631b")
+
+[node name="HitSound" type="AudioStreamPlayer2D" parent="."]
+stream = ExtResource("2_d7xod")
+bus = &"SFX"
+
+[connection signal="body_entered" from="." to="." method="_on_body_entered"]