Add simple rust wasm test

Needs an initial "npm install" and then "npm start" will build and launch it in the browser.

examples/rustwasmtest/src/lib.rs

@@ -0,0 +1,36 @@
+use wasm_bindgen::prelude::*;
+
+// Using a macro for now.  But there could be others ways to do that
+sixtyfps::sixtyfps! {
+    SuperSimple = Rectangle {
+        color: white;
+
+        Rectangle {
+            width: 100;
+            height: 100;
+            color: blue;
+        }
+        Rectangle {
+            x: 100;
+            y: 100;
+            width: (100);
+            height: {100}
+            color: green;
+        }
+        Image {
+            x: 200;
+            y: 200;
+            source: "../../examples/graphicstest/logo.png";
+        }
+    }
+}
+
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen(start))]
+pub fn wasm_main() {
+    // This provides better error messages in debug mode.
+    // It's disabled in release mode so it doesn't bloat up the file size.
+    #[cfg(debug_assertions)]
+    console_error_panic_hook::set_once();
+
+    SuperSimple::default().run();
+}