url-document-title.js

{
document.addEventListener("DOMContentLoaded", _=> {
  const observer = new MutationObserver(() => {
    console.log('document title got updated');
    observer.disconnect();
    document.title += ` ${document.URL}`;
    observer.observe(document.querySelector('title'), { childList: true });
  });

  document.title += ` ${document.URL}`;
  observer.observe(document.querySelector('title'), { childList: true }); 
});
}