add earcut to frame

Playground/frame.html

@@ -29,6 +29,7 @@
     <!-- Babylon.js -->
     <script src="https://preview.babylonjs.com/cannon.js"></script>
     <script src="https://preview.babylonjs.com/Oimo.js"></script>
+    <script src="https://preview.babylonjs.com/earcut.min.js"></script>
     <script src="https://preview.babylonjs.com/babylon.js"></script>
     <script src="https://preview.babylonjs.com/inspector/babylon.inspector.bundle.js"></script>