code: function createLineElement (line, elemType, classes) {
    let content = line;
    /* --- DEPRECATED FEATURE --- */
    const matches = line.match(/^(h\d) (.+)/);
    if (matches) {
      // Line starts with the name of a title element so let's use that
      elemType = matches[1];
      content = matches[2];
    }
    /* --- DEPRECATED FEATURE --- */
    const elem = document.createElement(elemType);
    elem.innerHTML = format(content);
    elem.classList.add(...classes);
    return elem;
  }
docs: /* Create an element (usually p, but also h1-h6) and format it.