Update index.html

public/index.html

@@ -15,7 +15,7 @@
 
 <!-- Starting an immersive WebXR session requires user interaction.
     We start this one with a simple button. -->
-<button onclick="activateXR()">Start Hit to Place Demo</button>
+<button onclick="activateXR()">Tap to Place AR Demo</button>
 <script>
 async function activateXR() {
   // Add a canvas element and initialize a WebGL context that is compatible with WebXR.