mode : 1 = images only, 2 = videos only, 3 = both images and videos
force : 0 = no force (default), 1 = overwrite existing thumbnails
verbose : 0 = only print missing thumbs (default), 1 = print all, 2 = print nothing
cfcache : 0 = do not clear cloudflare cache (default), 1 = clear cloudflare cache
```
For example, if you only want to generate thumbnails for image files without overwriting existing ones, you can run `yarn thumbs 1`, or if you want to generate thumbnails for both image and video files, while also overwriting existsing ones, you can run `yarn thumbs 3 1`.
You will also need to use this script to overwrite existing thumbnails if you want to change thumbnail size.