exp/audio: document the package being designed for small media files
exp/audio: document the package being designed for small media files

Change-Id: Icbe531369920f0a4b80c37622fb66d1bc4221377
Reviewed-on: https://go-review.googlesource.com/16230
Reviewed-by: David Crawshaw <a2f0bf29257797dd66800b4fbb9945c3e216c004@golang.org>

golang/mobile,golang/mobile,golang/mobile,golang/mobile