Fix #29: Add Rust display driver to See also section

Add link to push2_display crate on crates.io as mentioned in issue #29.
This provides a Rust implementation for the Push 2 display interface.

Author: Brody Nielsen

README.md

@@ -28,6 +28,7 @@ Please add an [issue](https://github.com/Ableton/push-interface/issues) with you
 * https://github.com/garrensmith/abletonpush
 * https://github.com/wookay/PushInterface.jl
 * https://github.com/ffont/push2-python
+* https://crates.io/crates/push2_display (Rust display driver)
 
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