Skip files already downloaded

It would be great when to be given an option if we want to skip the already downloaded files.

This is useful because when I am downloading a playlist that is constantly updated, 4K Downloaded would recognize the videos I have already downloaded and it would give me the freshest content.

Also if the app or windows crashes, and when 4K Downloader would be reopened with an empty download page, there would be no need to download the whole playlist again, or handpick the ones that have not been downloaded. 4K would recognize the downloaded videos from the playlists, and it would offer to download the rest,