Simple ai shooting PoC (#23)

src/physics_layers.rs

@@ -1,6 +1,7 @@
 use avian3d::prelude::PhysicsLayer;
+use bevy::reflect::Reflect;
 
-#[derive(PhysicsLayer, Clone, Copy, Debug, Default)]
+#[derive(PhysicsLayer, Clone, Copy, Debug, Default, Reflect)]
 pub enum GameLayer {
     #[default]
     Level,