feat: add music to the main scene and sfx for the npcs;

Scenes/GameScene/game_scene.tscn

@@ -14,6 +14,7 @@
 [ext_resource type="PackedScene" uid="uid://bdu180bpjrn5h" path="res://Scenes/Switch/switch.tscn" id="8_njm7v"]
 [ext_resource type="PackedScene" uid="uid://bqcsg2t581j7b" path="res://Scenes/TreasureChest/treasure_chest.tscn" id="9_bkvnf"]
 [ext_resource type="PackedScene" uid="uid://dsb83tlcapw8l" path="res://Scenes/NPC/npc.tscn" id="10_g3lhp"]
+[ext_resource type="AudioStream" uid="uid://bhl6upyji6aap" path="res://Ninja Adventure - Asset Pack/Musics/5 - Peaceful.ogg" id="15_rpdpv"]
 
 [sub_resource type="TileSetAtlasSource" id="TileSetAtlasSource_04h35"]
 texture = ExtResource("1_l6yvh")
@@ -863,6 +864,13 @@ limit_top = -144
 limit_right = 192
 limit_bottom = 160
 
+[node name="AudioStreamPlayer" type="AudioStreamPlayer" parent="." unique_id=1027726927]
+process_mode = 3
+stream = ExtResource("15_rpdpv")
+volume_db = -5.0
+autoplay = true
+parameters/looping = true
+
 [connection signal="pressed" from="PuzzleButton" to="LockedDoor" method="_on_puzzle_button_pressed"]
 [connection signal="unpressed" from="PuzzleButton" to="LockedDoor" method="_on_puzzle_button_unpressed"]