Browse for files on MacOS

[ybnd]

There's no decent non-Tkinter solution on MacOS (closest is this, but noope)

There's some issues with Tkinter on MacOS; workaround to get it working:

brew install python-tk

Actual Tkinter looks perfectly fine on MacOS, so NBD

File selector still errors out with "no file selected" though...

TODO:

• Document workaround
• Fix "no file selected" bug