Update public/place.html

public/place.html

@@ -17,7 +17,7 @@
 
 <!-- Starting an immersive WebXR session requires user interaction.
     We start this one with a simple button. -->
-<button onclick="activateXR()">Start Cube Demo</button>
+<button onclick="activateXR()">Start placing Demo</button>
 <script>
 async function activateXR() {
   // Add a canvas element and initialize a WebGL context that is compatible with WebXR.