Checklist

• I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• I have read the contribution

**Describe

Please add video length on the video thumbnail just like the official Developer app from Apple.

Right now, I can see the length if I click to go to detail screen, but I would have to do it one by one. It would be great to see the length of each video in a glance so that if i have like 15 minutes, I know which one I can watch.

From suggestion here, this should be implemented with audio_ffmpeg_params in write_videofile.

~/.config/youtube-dlg should just contain configuration files and not logs (which should go to $XDG_DATA_HOME/youtube-dlg/ ) nor youtube-dl binary (which should go to $XDG_CACHE_HOME).

Please also consider using appdirs instead of hardcoding ~/.config/

Summa