Add Matomo tracking code

[tjeerdijk]

Please add the Matomo tracking code listed below

<script> 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://openms.matomo.cloud/"; _paq.push(['setTrackerUrl', u+'matomo.php']); _paq.push(['setSiteId', '2']); var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.async=true; g.src='https://cdn.matomo.cloud/openms.matomo.cloud/matomo.js'; s.parentNode.insertBefore(g,s); })(); </script>

[tjeerdijk]

@copilot can you prepare a PR