Feature request: Download only thumbnail

[1RandomDev]

I'd really like an option to only download the thumbnail of a video in the format dropdown menu. The download itself can be achieved by adding the options writethumbnail:true and skip_download:true to yt-dlp, but then the .webp file has to be converted to a more usable format with ffmpeg.

[PikuZheng]

try this modify https://github.com/PikuZheng/metube/commit/63294bfe89c8d53a5119dc0996016fa04e148e22 It works but still a lot of work to be done