message: Add smooth scroll when click a toc link
  It doesn't support mobile, but fix the issue where the top bar was
  hiding the heading
diff: @@ -9,25 +9,34 @@ let lastClickElement = null;
  function handleTocClick(event){
  const target = event.target;
  + event.preventDefault();
  if(target.hasAttribute("href")){
  + const heading = document.querySelector(target.getAttribute('href'));
  + const rect = heading.getBoundingClientRect();
  + let mobileScrollOffset = 20;
  if(lastClickElement) lastClickElement.classList.remove('active');
  target.classList.add('active');
  lastClickElement = target;
  //only call if on mobile
  if(sidebar.classList.contains('visible')){
  - //set to false, so it doens't call preventDefault
  - mobileToggleEvent(event, false);
  + mobileToggleEvent(event);
  + mobileScrollOffset = 84;
  }
  +
  + window.scrollBy({
  + top: (heading.offsetTop - window.scrollY) - mobileScrollOffset,
  + behavior: 'smooth'
  + });
  +
  }
  }
  -function mobileToggleEvent(event, preventDefault){
  +function mobileToggleEvent(event){
  const bodyClassList = document.body.classList;
  -
  - if(preventDefault) event.preventDefault();
  + event.preventDefault();
  sidebar.classList.toggle('visible');
  overlay.classList.toggle('visible');
  bodyClassList.toggle('no-scroll');
  