add minimal example

src/lib.rs

@@ -9,6 +9,7 @@
 #![feature(const_destruct)]
 #![feature(portable_simd)]
 #![feature(gen_blocks)]
+#![feature(associated_type_defaults)]
 
 pub mod core;
 pub mod layout;

src/winit/mod.rs

@@ -31,7 +31,7 @@ pub struct DefaultUi {
 }
 
 pub trait DefaultUiState: 'static {
-    type Event: 'static;
+    type Event: 'static = ();
     fn new(ui: DefaultUi, proxy: Proxy<Self::Event>) -> Self;
     fn ui(&mut self) -> &mut DefaultUi;
     #[allow(unused_variables)]