Mac OS support

[Animeshz]

Need collaborators / contributors for testing and working on extending the library to support Mac OS.

Unfortunately I have zero experience with Apple products and don't have access to a Mac right now, so I couldn't test the library either way.

The codebase is organized to easily integrate the support, one can work on either Java, C++ (JNI side) or Kotlin (K/Native side) whichever is more familiar to him/her. The keyboard-kt/src/jvmMain/jni/{platform}-{arch}/ is where the platform specific JNI code reside, and the Kotlin/Native code is present in keyboard-kt/src/{platform}{arch}Main/ as usual.

To cross-build for the JVM packaging we can use multiarch/crossbuild, and gradle to automate the build process as we've did for Windows and Linux currently.

If somebody has any idea or suggestions drop it below! A small contribution may help the project to pick up the momentum to get ready for the complete implementation.

[grsky360]

You may want to check this
https://chromium.googlesource.com/chromium/src/+/master/chrome/browser/extensions/global_shortcut_listener_mac.mm