add gtag.js for GA
add gtag.js for GA

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-61649690-1"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'UA-61649690-1');
</script>
izawaryu/izawaryu.github.io,izawaryu/izawaryu.github.io