update setting

themes/default/index.html

@@ -41,6 +41,17 @@
     </footer>
   </div>
   <script src="fontawesome/js/all.js" data-auto-replace-svg="nest"></script>
+  {% if google_analytics_id %}
+    <!-- Google tag (gtag.js) -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id={{ google_analytics_id }}"></script>
+    <script>
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+
+      gtag('config', '{{ google_analytics_id }}');
+    </script>
+  {% endif %}
   <script src="./scripts.js"></script>
 </body>
 </html>