Alpha release

Hi there!

After a year of experimenting with MusicKit, I slowly understand the framework better and the relevant structures and methods. While the framework is excellent, parts are still missing compared to the Apple Music API, specifically related to library items.

MusadoraKit is my attempt to fill in the gap and provide a much better experience built on top of MusicKit. There are custom structures with similar implementation to MusicKit, which is the framework's alpha release!

I will continue working on it every month and make it the ultimate Swift Package if you use MusicKit in your app!