Update public/webXR/three.html

public/webXR/three.html

@@ -13,9 +13,7 @@
 
 <!-- Starting an immersive WebXR session requires user interaction.
     We start this one with a simple button. -->
-<button onclick="activateXR()">Start Cube Demo</button>
 <script>
-async function activateXR() {
   // ------------------------------------------------
 // BASIC SETUP
 // ------------------------------------------------
@@ -64,7 +62,6 @@ var render = function () {
 
 render();
 
-}
 </script>
 </body>
 </html>