Файлы разметки узел.

const { readdir, readFile, writeFile } = require("fs/promises");
const matter = require("gray-matter");
const { stringify } = require("yaml");

const directory = "<YOUR-DIRECTORY>";

async function updateFrontMatter(filename) {
  const filepath = `${directory}/${filename}`;

  const { data: frontMatter, content } = matter(await readFile(filepath));

  // remove desc attribute
  if (frontMatter.desc === "") {
    delete frontMatter["desc"];
  }

  // parse created date attribute and convert it as timestamp
  if (typeof frontMatter.created === "string") {
    frontMatter.created = new Date(frontMatter.created).getTime();
  }

  const newContent = `---\n${stringify(frontMatter)}---\n${content}`;

  await writeFile(filepath, newContent);

  console.log(`- [x] ${filepath}`);
}

async function main() {
  const filenames = await readdir(directory);
  const markdownFilenames = filenames.filter((f) => f.endsWith(".md"));

  await Promise.all(markdownFilenames.map(updateFrontMatter));
}

main().catch(console.error);
KostasX