Added google analytics script

Author: NiharikaHari

_includes/head.html

@@ -18,4 +18,14 @@
     <script src="/js/main.js" defer></script>
     <!-- <script src="https://cdn.tailwindcss.com"></script> -->
 
+    <!-- Google tag (gtag.js) -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-FPK1D696LN"></script>
+    <script>
+        window.dataLayer = window.dataLayer || [];
+        function gtag() { dataLayer.push(arguments); }
+        gtag('js', new Date());
+
+        gtag('config', 'G-FPK1D696LN');
+    </script>
+
 </head>