Minor fix - Yew example (#1852)

https://github.com/yewstack/yew/discussions/3688

The missing body tag causes an error while serving the website

Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com>

examples/wasm-example/index.html

@@ -6,4 +6,5 @@
     <link data-trunk rel="inline" href="index.js" />
     <title>Subxt Examples Yew App</title>
   </head>
-</html>
+  <body></body>
+</html>