Rename "event" module to be plural "events.rs"

src/events.rs

@@ -0,0 +1,21 @@
+use bevy::prelude::*;
+
+/// Signals that the player's ship has been destroyed.
+/// Used when the player collides with an asteroid.
+#[derive(Event)]
+pub(crate) struct ShipDestroy;
+
+/// Signals that a particular asteroid has been destroyed.
+/// Used to split (or vanish) an asteroid when a bullet strikes it.
+#[derive(Event)]
+pub(crate) struct AsteroidDestroy(pub Entity);
+
+// TODO: BulletDestroy
+// Which depends on the still-pending Bullet component creation.
+
+/// Signals that a particular bullet has been destroyed.
+/// Used to despawn the bullet after it strikes an Asteroid.
+///
+/// TODO: Maybe use it for lifetime expiration (which is also a TODO item).
+#[derive(Event)]
+pub(crate) struct BulletDestroy(pub Entity);