website/playground/markdown.js/formatMarkdown
function formatMarkdown({
  input,
  output,
  output2,
  doc,
  version,
  url,
  options,
  cliOptions,
  full,
}) {
  const syntax = getMarkdownSyntax(options);
  const optionsString = formatCLIOptions(cliOptions);
  const isIdempotent = !output2 || output === output2;

  return [
    `**Prettier ${version}**`,
    `[Playground link](${url})`,
    optionsString === "" ? null : codeBlock(optionsString, "sh"),
    "",
    "**Input:**",
    codeBlock(input, syntax),
    ...(doc ? ["", "**Doc:**", codeBlock(doc, "js")] : []),
    ...(output === undefined
      ? []
      : ["", "**Output:**", codeBlock(output, syntax)]),
    ...(isIdempotent
      ? []
      : ["", "**Second Output:**", codeBlock(output2, syntax)]),
    ...(full ? ["", "**Expected behavior:**", ""] : []),
  ]
    .filter((part) => part !== null)
    .join("\n");
}