Add matomo (INRIA#607)

Author: lesteve

jupyter-book/_static/matomo.js

@@ -0,0 +1,15 @@
+var _paq = window._paq = window._paq || [];
+/* tracker methods like "setCustomDimension" should be called before "trackPageView" */
+_paq.push(['trackPageView']);
+_paq.push(['enableLinkTracking']);
+(function() {
+    var u = "https://piwik.inria.fr/";
+    _paq.push(['setTrackerUrl', u + 'piwik.php']);
+    _paq.push(['setSiteId', '127']);
+    var d = document,
+        g = d.createElement('script'),
+        s = d.getElementsByTagName('script')[0];
+    g.async = true;
+    g.src = u + 'piwik.js';
+    s.parentNode.insertBefore(g, s);
+})();