Add biome for js lint and formatting.

assets/js/tracking.js

@@ -3,6 +3,7 @@
  * A JavaScript file for analytic tracking.
  */
 
+
 import * as params from '@params';
 
 const cookiebanner = params.cookieConsent;
@@ -12,6 +13,8 @@ const matomoTrackingApiUrl = 'https://' + params.piwikTrackerUrl + '/matomo.php'
 const googleAnalytics = params.GoogleAnalytics;
 
 if (idSite) {
+  // biome-ignore lint/style/useConst: Google code.
+  // biome-ignore lint/suspicious/noAssignInExpressions: Google code.
   let _paq = window._paq = window._paq || [];
 
   if (cookiebanner) {