Integrate Google Analytics in 404.html

Added Google Analytics tracking script to 404 page.

Author: kdippan

404.html

@@ -6,6 +6,15 @@
     <title>404 - Page Not Found | GitHub Profile Finder</title>
     <link rel="icon" type="image/png" href="assets/favicon-32x32.png">
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
+    <!-- Google tag (gtag.js) -->
+<script async src="https://www.googletagmanager.com/gtag/js?id=G-NT1CD907W8"></script>
+<script>
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+
+  gtag('config', 'G-NT1CD907W8');
+</script>
     <style>
         * {
             margin: 0;