message: deserialize headers from html back to markdown
diff: @@ -71,8 +71,20 @@ function parseCodeBlock(n, partCreator) {
  return parts;
  }
  +function parseHeader(el, partCreator) {
  + const depth = parseInt(el.nodeName.substr(1), 10);
  + return partCreator.plain("#".repeat(depth) + " ");
  +}
  +
  function parseElement(n, partCreator, state) {
  switch (n.nodeName) {
  + case "H1":
  + case "H2":
  + case "H3":
  + case "H4":
  + case "H5":
  + case "H6":
  + return parseHeader(n, partCreator);
  case "A":
  return parseLink(n, partCreator);
  case "BR":
  