[Feature request] option to add local playlist to another playlist & add all channel videos to playlist

[BatmanDrinkingLean]

the option to add all videos of a playlist created on YouTube to a local playlist is already in pipepipe, but local playlists themselves lack this option. currently, you can't add all videos of a local playlist to another playlist. i think this would be a good feature

also i think that an option to add all the uploaded videos of a channel to a local playlist would be useful, if possible.

much love to pipepipe.