Add Google Analytics script to page layout

src/routes/+layout.svelte

@@ -27,6 +27,18 @@
 </script>
 
 <svelte:head>
+    <!-- Google tag (gtag.js) -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-36F29PDKRT"></script>
+    <script>
+        window.dataLayer = window.dataLayer || [];
+        function gtag() {
+            dataLayer.push(arguments);
+        }
+        gtag('js', new Date());
+
+        gtag('config', 'G-36F29PDKRT');
+    </script>
+
     <title>{merged.title}</title>
     <meta name="description" content={merged.description ?? ''} />
     <link rel="canonical" href={merged.canonical} />