CXX-1889 add analytics

Author: kevinAlbs

docs/themes/mongodb/layouts/partials/assets/analytics.html

@@ -20,3 +20,13 @@
 else if (window.attachEvent) window.attachEvent('onload', async_load);
 })();
 </script>
+
+<!-- Global site tag (gtag.js) - Google Analytics -->
+<script async src="https://www.googletagmanager.com/gtag/js?id=UA-7301842-14"></script>
+<script>
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+
+  gtag('config', 'UA-7301842-14');
+</script>