[DOCS] add Matomo analytics (#20438)

.travis.yml

@@ -9,7 +9,7 @@ before_script:
 # the `install` step will run `bundle install` by default.
 script:
   - bundle exec jekyll build
-  - bundle exec htmlproofer ./_site --assume-extension --allow-hash-href
+  - bundle exec htmlproofer ./_site --assume-extension --allow-hash-href --empty-alt-ignore
 
 env:
   global:

_includes/head.html

@@ -22,5 +22,20 @@
 {% for x in page.js %}{% capture target %}{% include link.html url=x %}{% endcapture %}
     <script src="{{ target | strip }}"></script>
 {% endfor %}
-  
+  <!-- Matomo -->
+  <script type="text/javascript">
+    var _paq = window._paq || [];
+    /* tracker methods like "setCustomDimension" should be called before "trackPageView" */
+    _paq.push(['trackPageView']);
+    _paq.push(['enableLinkTracking']);
+    (function() {
+      var u="https://matomo.ethereum.org/";
+      _paq.push(['setTrackerUrl', u+'matomo.php']);
+      _paq.push(['setSiteId', '22']);
+      var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
+      g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s);
+    })();
+  </script>
+  <noscript><p><img src="https://matomo.ethereum.org/matomo.php?idsite=22&amp;rec=1" style="border:0;" alt="" /></p></noscript>
+  <!-- End Matomo Code -->
 </head>