Request: add nib file example

[programmingkidx]

Hi, I am wishing for a nib file example using Go. I think most people out there will be making their interface using Xcode rather than thru code, so this example could help a lot of people out.

[progrium]

I'd love it if somebody could add a dedicated example for this. The (currently broken) opengl example has the basic idea:
https://github.com/progrium/macdriver/blob/main/macos/_examples/opengl/main.go#L78