Documentation uses 'Sound' but context defines 'Audio'

[azaroth42]

The name for the class of auditory digital resources given in 3.2.2 of the model is "Sound".

The mapping provided in the context document is "Audio"

Given that the documentation is normative, the "Sound" mapping should be added to the context document.

Initially raised within IIIF

[azaroth42]

Also, mea culpa! (blush)