src/language-markdown/printer-markdown.js/printUrl
function printUrl(url, dangerousCharOrChars = []) {
  const dangerousChars = [
    " ",
    ...(Array.isArray(dangerousCharOrChars)
      ? dangerousCharOrChars
      : [dangerousCharOrChars]),
  ];
  return new RegExp(dangerousChars.map((x) => `\\${x}`).join("|")).test(url)
    ? `<${url}>`
    : url;
}