This is just something I hacked together to create an audiobook file out of CD audio files (complete with chapter marking metadata!)
Works great when used in combination with https://github.com/kentcdodds/podcastify-dir
npx https://gist.github.com/kentcdodds/e07f9106c63cc13a75adb0157700eb5b ./path-to-sorted-mp3s