chore: update app.js script source with version query parameter in demo index

Author: tiw302

docs/demo/index.html

@@ -66,7 +66,7 @@ <h1>cjsonx</h1>
     </div>
 
     <script src="cjsonx_wasm.js"></script>
-    <script src="app.js"></script>
+    <script src="app.js?v=2"></script>
 </body>
 
 </html>