Make egui_demo_app native window size larger by default

egui_demo_app/src/main.rs

@@ -10,6 +10,8 @@ fn main() {
     let options = eframe::NativeOptions {
         drag_and_drop_support: true,
 
+        initial_window_size: Some([1280.0, 1024.0].into()),
+
         #[cfg(feature = "wgpu")]
         renderer: eframe::Renderer::Wgpu,