Sorry for taking so long to reply... I don't know how I missed this :)
Mentioning YouTubeFisher in the readme file and your project description is enough, and I see you did both... so everything is fine.
I'm following your project for a while now and will contact you soon related some code which is not ours (audio extraction code) and I'm creating a NuGet package for it. We don't maintain this part of the code so it would be better if we separate it in a
stand-alone library; and same for you. It's also under GNU license by the way.