Update index.html

Author: WeihanLi

src/index.html

@@ -8,6 +8,7 @@
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <link rel="icon" type="image/x-icon" href="favicon.ico">
   <script src="assets/config.js"></script>
+  <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9932692180808471" crossorigin="anonymous"></script>
   <!-- Google Analytics -->
   <script>
     window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;