Update index.html

index.html

@@ -6,6 +6,13 @@
             eruda.init();
         </script>
       <!-- Google tag (gtag.js) -->
+      <!-- Google Tag Manager -->
+<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
+new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
+j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
+'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+})(window,document,'script','dataLayer','GTM-NDL2LKLQ');</script>
+<!-- End Google Tag Manager -->
 <script async src="https://www.googletagmanager.com/gtag/js?id=G-2M35HBEEVH"></script>
 <script>
   window.dataLayer = window.dataLayer || [];