diff --git a/doc/theme/head.hbs b/doc/theme/head.hbs
new file mode 100644
index 0000000..c4dfade
--- /dev/null
+++ b/doc/theme/head.hbs
@@ -0,0 +1,9 @@
+<!-- Google tag (gtag.js) -->
+<script async src="https://www.googletagmanager.com/gtag/js?id=G-X2X3EDGCM2"></script>
+<script>
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+
+  gtag('config', 'G-X2X3EDGCM2');
+</script>