[Cin] OT: comments from youtube can be saved, too

[Andrea paz]

@Andrew Randrianasulu
 I agree with everything you say.
Thanks also for ytdlp_nest_comments.py, I did not know it.

@Stefan de Konink
Some time ago a professional (from whose request the sync via timecode
was derived) said that if CinGG could synchronize all audio/video
files (not in the timeline, but in Resources window) with an external
audio and then delete the embedded audio leaving only the external
audio, CinGG could be used in the professional field.