Small documentation updates

README.md

@@ -4,4 +4,5 @@ A friendly rust interface for [Apple's Core Audio API](https://developer.apple.c
 
 This crate aims to expose and wrap the functionality of the original C API in a zero-cost, safe, Rust-esque manner.
 
-If you just want direct access to the unsafe bindings, use [coreaudio-sys](https://crates.io/crates/coreaudio-sys).
+If you just want direct access to the Core Audio APIs,
+use the appropriate crates of the [objc2 project](https://crates.io/crates/objc2).

src/lib.rs

@@ -5,8 +5,9 @@
 //!
 //! Read the CoreAudio Overview [here](https://developer.apple.com/library/mac/documentation/MusicAudio/Conceptual/CoreAudioOverview/Introduction/Introduction.html).
 //!
-//! Currently, work has only been started on the [audio_unit](./audio_unit/index.html) module, but
-//! eventually we'd like to cover at least the majority of the C API.
+//! Currently, this crate provides the [audio_unit] module that covers the
+//! [Audio Unit framework](https://developer.apple.com/documentation/audiounit)
+//! (now part of [Audio Toolbox](https://developer.apple.com/documentation/AudioToolbox)).
 
 #[macro_use]
 extern crate bitflags;