AudioKit is documented in a few different, but related ways.
By using inline comments, AudioKit is self-documenting, and the help panel within Xcode should be populated by this style of autogenerated documentation. Inline comments are lines that begin with three slashes //github.com/ or comment blocks that begin with /** and end with */. For the most part, we prefer three asterisks.
Inline comments are also parsed by the "jazzy" documentation generator which provides us web based documentation.
We try to include a README folder in every directory of AudioKit to describe folders' contents and to provide some basic quickstart information.
README files often contain TODO sections which contain things that could or should improve the material in that folder.
Playgrounds contain bite-size examples of AudioKit and serve as tutorials for many of AudioKit's core concepts and capabilities. There are over 100 playgrounds which cover basic tutorials, synthesis, physical modeling, file playback, MIDI, effects, filters, and analysis. The playgrounds can be perused on Github, or on AudioKit.io (many with demonstration videos).
There are many sample projects included in AudioKit's Examples folder. The examples have some extra documentation in their READMEs and on the audiokit.io website.