Add Matomo tag manager

hdyc-svelte/src/routes/+layout.svelte

@@ -323,6 +323,16 @@
 <svelte:head>
   <meta name="viewport" content="width=device-width, initial-scale=1" />
   <link rel="icon" href="/favicon.png" />
+  <!-- Matomo Tag Manager -->
+  <script>
+    var _mtm = window._mtm = window._mtm || [];
+    _mtm.push({'mtm.startTime': (new Date().getTime()), 'event': 'mtm.Start'});
+    (function() {
+      var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
+      g.async=true; g.src='https://matomo.howdoyouconvert.com/js/container_B3r877Kn.js'; s.parentNode.insertBefore(g,s);
+    })();
+  </script>
+  <!-- End Matomo Tag Manager -->
 </svelte:head>
 
 <header class="site-header">