different ammo per head (#30)

src/npc.rs

@@ -34,7 +34,13 @@ fn init(mut commands: Commands, query: Query<(Entity, &EnemySpawn)>, heads_db: R
                 Hitpoints::new(100),
                 Npc,
                 ActiveHead(id),
-                ActiveHeads::new([Some(HeadState::new(id, 10)), None, None, None, None]),
+                ActiveHeads::new([
+                    Some(HeadState::new(id, heads_db.as_ref())),
+                    None,
+                    None,
+                    None,
+                    None,
+                ]),
                 Ai,
             ))
             .observe(on_kill);