Add supports for MacOS

[akif999]

Add supports for MacOS X.

If we intend to switch to HHKB level, it may not be necessary to change the firmware itself, so in that case we will add information for use with MacOS to the document.

Even if we assume a complete Windows keyboard, it can be used by adding settings as shown on the website below, so it may be a good idea to guide users there first.
https://office-m-blog.com/blog/2015/01/22/2015-01-22/

[sago35]

@akif999
Do you know what firmware changes are required to create a keyboard specifically for macOS? Would it be sufficient to simply add some key definitions?

Also, is it possible to detect the OS when the keyboard is connected? If so, we could write various processes accordingly.

As you suggested, adding documentation would also be a good idea.