feat: add GA (#6)

Author: thisthat

.gitignore

@@ -3,3 +3,5 @@
 /data/
 /node_modules/
 /tmp
+
+.idea

layouts/partials/hooks/head-end.html

@@ -14,3 +14,11 @@
 {{ else if in .RelPermalink "/docs/" -}}
   <link rel="canonical" href="{{ .RelPermalink | absURL}}"/>
 {{- end}}
+<!-- Google tag (gtag.js) -->
+<script async src="https://www.googletagmanager.com/gtag/js?id=G-SJLS2F2J2B"></script>
+<script>
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+  gtag('config', 'G-SJLS2F2J2B');
+</script>