added coin spawner

coin_spawner.tscn

@@ -0,0 +1,12 @@
+[gd_scene load_steps=2 format=3 uid="uid://1shngq3vrbu"]
+
+[ext_resource type="Script" uid="uid://bn2u3tc7cwlhc" path="res://Scripts/coin_spawner.gd" id="1_7h776"]
+
+[node name="CoinSpawner" type="Marker3D"]
+script = ExtResource("1_7h776")
+
+[node name="Timer" type="Timer" parent="."]
+wait_time = 0.1
+autostart = true
+
+[connection signal="timeout" from="Timer" to="." method="_on_timer_timeout"]