add gtm

index.html

@@ -452,4 +452,18 @@ <h1>Game Over</h1>
     }
     startGame();
   </script>
+  <!-- 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-TLRXF9F");
+  </script>
+  <!-- End Google Tag Manager -->
 </html>