archive/directives/process/process_html_directives.js
function consume_doctype_or_comment (proc_stack) {
  let html = "<!";
  proc_stack.tSkip(2);
  html += proc_stack.tAcceptUntil(">") + proc_stack.tAccept();
  return html;
}
function consume_doctype_or_comment (proc_stack) {
  let html = "<!";
  proc_stack.tSkip(2);
  html += proc_stack.tAcceptUntil(">") + proc_stack.tAccept();
  return html;
}
Called after `<!`