for smart mode - add option to set subfolder for playlist download

I would like to download playlists in their own subfolder. Right now i have to set smart mode options each time. Ideal way: i paste the link, 4KDownloader asks "download as playlist?" and it has optional field "Subfolder". If it is not empty it creates a directory for the playlist.

Also would like an option to append number to video file names to preserve order as in initial playlists.