add: google analytics

index.html

@@ -7,6 +7,14 @@
     <link rel="stylesheet" href="style.css">
     <script defer src="script.js"></script>
     <script defer src="facts_script.js"></script>
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-DKNRQ6ZC7Q"></script>
+    <script>
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      
+      gtag('js', new Date());
+      gtag('config', 'G-DKNRQ6ZC7Q');
+    </script>
     <title>Strona o wiedźmach</title>
 </head>