Added more sound effects. Added initial weapon muzzle fire logic.

AlientAttack.MonoGame/Things/Muzzles/Muzzle.cs

@@ -0,0 +1,9 @@
+using Microsoft.Xna.Framework;
+
+namespace AlienAttack.MonoGame.Things.Muzzles;
+
+public readonly struct Muzzle(MuzzleId id, Vector2 localPx)
+{
+    public MuzzleId Id { get; } = id;
+    public Vector2 LocalPx { get; } = localPx;
+}