custom plugin

src/main.rs

@@ -1,11 +1,7 @@
 use bevy::prelude::*;
 
 fn main() {
-    App::new()
+    App::new().add_plugins((DefaultPlugins, HelloPlugin)).run();
-        .add_plugins(DefaultPlugins)
-        .add_systems(Startup, add_people)
-        .add_systems(Update, (hello_world, greet_people).chain())
-        .run();
 }
 
 fn hello_world() {
@@ -29,3 +25,12 @@ fn greet_people(query: Query<&Name, With<Person>>) {
         println!("hello {}!", name.0);
     }
 }
+
+pub struct HelloPlugin;
+
+impl Plugin for HelloPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, add_people)
+            .add_systems(Update, (hello_world, greet_people).chain());
+    }
+}