[FLINK-25915][docs] Add Matomo tracking code to base layout
diff --git a/docs/layouts/_default/baseof.html b/docs/layouts/_default/baseof.html
index b5c8149..733bf1b 100644
--- a/docs/layouts/_default/baseof.html
+++ b/docs/layouts/_default/baseof.html
@@ -23,6 +23,25 @@
   {{ hugo.Generator }}
   {{ partial "docs/html-head" . }}
   {{ partial "docs/inject/head" . }}
+  <!-- Matomo -->
+  <script>
+    var _paq = window._paq = window._paq || [];
+    /* tracker methods like "setCustomDimension" should be called before "trackPageView" */
+    /* We explicitly disable cookie tracking to avoid privacy issues */
+    _paq.push(['disableCookies']);
+    /* Measure a visit to flink.apache.org and nightlies.apache.org/flink as the same visit */
+    _paq.push(["setDomains", ["*.flink.apache.org","*.nightlies.apache.org/flink"]]);
+    _paq.push(['trackPageView']);
+    _paq.push(['enableLinkTracking']);
+    (function() {
+      var u="//matomo.privacy.apache.org/";
+      _paq.push(['setTrackerUrl', u+'matomo.php']);
+      _paq.push(['setSiteId', '1']);
+      var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
+      g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s);
+    })();
+  </script>
+  <!-- End Matomo Code -->
 </head>
 
 <body dir={{ .Site.Language.LanguageDirection }}>