docs: bevy require components

It's best practice since 0.15 to use Require Components instead of Bundles. Required Components are cached on the archetype graph, meaning computing what required components are necessary for a given type of insert only happens once.

skills/bevy-ecs-expert/SKILL.md

@@ -83,25 +83,27 @@ fn main() {
 
 ## Examples
 
-### Example 1: Spawning Entities with Bundles
+### Example 1: Spawning Entities with Require Component
 
 ```rust
-#[derive(Bundle)]
-struct PlayerBundle {
-    player: Player,
-    velocity: Velocity,
-    sprite: SpriteBundle,
+use bevy::prelude::*;
+
+#[derive(Component, Reflect, Default)]
+#[require(Velocity, Sprite)]
+struct Player;
+
+#[derive(Component, Default)]
+struct Velocity {
+    x: f32,
+    y: f32,
 }
 
 fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
-    commands.spawn(PlayerBundle {
-        player: Player,
-        velocity: Velocity { x: 10.0, y: 0.0 },
-        sprite: SpriteBundle {
-            texture: asset_server.load("player.png"),
-            ..default()
-        },
-    });
+    commands.spawn((
+        Player,
+        Velocity { x: 10.0, y: 0.0 },
+        Sprite::from_image(asset_server.load("player.png")), 
+    ));
 }
 ```