Example for using the Keyboard or Mouse as a boot device

To start off. Thanks for this awesome library and MacroPad. I've been having an absolute blast with it for the last week.

I may be able to help out with the example but I'm not exactly sure where to start.
I want to use the keyboard functions on the RP2040 to interact with GRUB (Dual boot windows and linux selection) but it seems like whatever I do, I cant get GRUB to detect the keyboard as a boot device.

[https://docs.circuitpython.org/en/latest/shared-bindings/usb_hid/index.html#usb_hid.enable](https://docs.circuitpython.org/en/latest/shared-bindings/usb_hid/index.html#usb_hid.enable)

I've enabled the `usb_hid` as stated in the docs about but either the host never requests the boot device or the device isn't reporting it correctly.

I added `usb_hid.enable((Device.KEYBOARD), boot_device=1) # 1 for a keyboard` to my `boot.py` and confirmed its being run, but when I call `usb_hid.get_boot_device()` from `code.py` it's always 0.

Hoping there is a simple example thats known to work.

Just as a note. My PC setup is not conventional, so there is a good possibility that its something weird not related to CircuitPython or this lib.

Start with the linked usb_hid.enable documentation and the reported boot.py and code.py calls, then check how get_boot_device() is expected to behave for the RP2040 keyboard device. Verify the behavior with GRUB on a comparable setup and document a confirmed working example or the relevant limitation.

Written by the indexing model from the issue text.