Restore matomo tracking in docs

docs/matomo-tracking.js

+var _paq = window._paq || [];
+/* tracker methods like "setCustomDimension" should be called before "trackPageView" */
+_paq.push(['disableCookies']); // évite de mettre en place un bandeau RGPD
+_paq.push(['trackPageView']);
+_paq.push(['enableLinkTracking']);
+(function() {
+var u="//stasi.g-eau.fr/";
+_paq.push(['setTrackerUrl', u+'matomo.php']);
+_paq.push(['setSiteId', '1']);
+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);
+})();
\ No newline at end of file

scripts/mkdocs-postprocess.js

 'use strict';
 
 /**
- * copies Mathjax to src/assets/docs/javascripts after doc was built by MkDocs
+ * copies extra javascripts (MathJax, matomo-tracking) to src/assets/docs/javascripts after doc was built by MkDocs
  */
 
 const fs = require('fs-extra');
 
-const destPath = "src/assets/docs/javascripts/mathjax";
+const destPath = "src/assets/docs/javascripts";
+const destPathMJ = destPath + "/mathjax";
 
 // empty destination folder
 fs.emptyDirSync(destPath);
 
 // create destination subfolders
-fs.ensureDirSync(destPath + "/fonts/HTML-CSS/TeX/", { recursive: true });
+fs.ensureDirSync(destPathMJ + "/fonts/HTML-CSS/TeX/", { recursive: true });
 
 // copy required files only
-fs.copySync("node_modules/mathjax/MathJax.js", destPath + "/MathJax.js");
-fs.copySync("node_modules/mathjax/config", destPath + "/config");
-fs.copySync("node_modules/mathjax/jax", destPath + "/jax");
-fs.copySync("node_modules/mathjax/fonts/HTML-CSS/TeX/woff", destPath + "/fonts/HTML-CSS/TeX/woff");
-fs.copySync("node_modules/mathjax/fonts/HTML-CSS/TeX/otf", destPath + "/fonts/HTML-CSS/TeX/otf");
+fs.copySync("node_modules/mathjax/MathJax.js", destPathMJ + "/MathJax.js");
+fs.copySync("node_modules/mathjax/config", destPathMJ + "/config");
+fs.copySync("node_modules/mathjax/jax", destPathMJ + "/jax");
+fs.copySync("node_modules/mathjax/fonts/HTML-CSS/TeX/woff", destPathMJ + "/fonts/HTML-CSS/TeX/woff");
+fs.copySync("node_modules/mathjax/fonts/HTML-CSS/TeX/otf", destPathMJ + "/fonts/HTML-CSS/TeX/otf");
+
+fs.copySync("docs/matomo-tracking.js", destPath + "/matomo-tracking.js");