First sound! Added ship explosion sound effect

It's a simple one-shot sound clip that gets dispatched as one more part
of the ship impact routine.

The GameAssets struct has been updated to have an array of handles for
audio assets (just the one, for now).

This sound file, and the next several, are all from Kenney
(www.kenney.nl).

src/objects.rs

@@ -3,6 +3,7 @@
 //! Asteroids, the player's ship, and such.
 
 use bevy::{
+    audio::{AudioPlayer, PlaybackSettings},
     camera::visibility::Visibility,
     ecs::{
         component::Component,
@@ -232,5 +233,11 @@ pub fn ship_impact_listener(
         // STEP 4: Respawn player (teleport them to the origin)
         player.0.translation = Vec3::ZERO;
         player.1.0 = Vec2::ZERO;
+
+        // STEP 5: Play crash sound
+        commands.spawn((
+            AudioPlayer::new(game_assets.wreck_sound()),
+            PlaybackSettings::ONCE,
+        ));
     }
 }