Add Google Analytics Tracking

[alangshur]

Let's add the following Google Analytics tracking script to HTML on landing page:

<script async src="https://www.googletagmanager.com/gtag/js?id=UA-150189838-1"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'UA-150189838-1');
</script>