Add bookmark feature

[Abraka]

Checklist

• [x] I made sure that there are no existing issues - open or closed - which I could contribute my information to.
• [x] I have read the FAQ and my problem isn't listed.
• [x] I'm aware that this is a request for Tubular itself and that requests for adding a new service need to be made in vanilla NewPipeExtractor.
• [x] I have taken the time to fill in all the required details. I understand that the feature request will be dismissed otherwise.
• [x] This issue contains only one feature request.
• [x] I have read and understood the vanilla NewPipe contribution guidelines.

Feature description

It would be nice to have an ability to add specific channel to some kind of bookmark list, so when I will run tubular next, it will be possible to choose from different channels which will be listed in bookmark tab. Thx.

Why do you want this feature?

Easy and fast access to most visit channels.

Why is the feature relevant to this fork?

It will make this fork more awesome of course :)

Additional information

No response

[dftf-stu]

@Abraka : sounds like you want to create folders and put channels into them, to organise them by theme or category?

If so, your request may be a duplicate of #273 . If so, you can close this ticket