Vendor dependencies for 0.3.0 release

vendor/bevy/examples/app/without_winit.rs

@@ -0,0 +1,14 @@
+//! Create an application without winit (runs single time, no event loop).
+
+use bevy::{prelude::*, winit::WinitPlugin};
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins.build().disable::<WinitPlugin>())
+        .add_systems(Update, setup_system)
+        .run();
+}
+
+fn setup_system(mut commands: Commands) {
+    commands.spawn(Camera3d::default());
+}