code: function wrapInner(parent, wrapper) {
      if (typeof wrapper === "string") wrapper = document.createElement(wrapper);
  
      parent.appendChild(wrapper);
  
      while (parent.firstChild !== wrapper) wrapper.appendChild(parent.firstChild);
    }
docs: /*const wrapInner = (el, wrapper_el) => { // doesn't work on IE/Edge, f…
  while (el.firstChild)
  wrapper_el.append(el.firstChild);
  el.append(wrapper_el);
  }