diff --git a/docs/index.html b/docs/index.html
index 6532703..59da9bf 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -5,6 +5,14 @@
     <script language="javascript" src="lib.js"></script>
     <script language="javascript" src="out.js"></script>
     <link rel="stylesheet" href="style.css">
+
+    <!-- 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-5KB8BLT');</script>
+    <!-- End Google Tag Manager -->
   </head>
   <body>
   </body>
