create islands accordding to a rulee

gistfile1.txt

    <script>
        var islands = document.querySelectorAll("h3 + ul"); // returns array
        islands.forEach(function (child) {
          let par = child.parentNode ;
          let pre  = child.previousElementSibling;
          var sec = document.createElement('section');
          par.replaceChild(sec,pre);
          sec.appendChild(pre);
          sec.appendChild(child);
          sec.setAttribute("class","standout" );
        })
    </script>