feat(shields): Add Fifi Shield Support

[hmngwy]

Board/Shield Check-list

• This board/shield is tested working on real hardware
• Definitions follow the general style of other shields/boards upstream (Reference)
• .zmk.yml metadata file added
• Proper Copyright + License headers added to applicable files (Generally, we stick to "The ZMK Contributors" for copyrights to help avoid churn when files get edited)
• General consistent formatting of DeviceTree files
• Keymaps do not use deprecated key defines (Check using the upgrader tool)
• &pro_micro used in favor of &pro_micro_d/a if applicable
• If split, no name added for the right/peripheral half
• .conf file has optional extra features commented out

[hmngwy]

@Nicell added the missing copyright lines, updated to 2022, ditched the changes to build.yml

[Nicell]

Please remove the fifi_left.conf and fifi_right.conf files! Otherwise I think this definition looks good. Thanks. You can re-request my review after updating.

[petejohanson]

@hmngwy Please feel free to re-open this once you have a chance to address the item from @Nicell and this is ready for review again.

Thanks!

[hmngwy]

Hi @petejohanson, rebased with main and then reapplied my changes, but I'm getting the below:

FATAL ERROR: command exited with status 1: /usr/local/bin/cmake -DWEST_PYTHON=/usr/bin/python3 -B/__w/zmk/zmk/build -S/__w/zmk/zmk/app -GNinja -DBOARD=nice_nano -DSHIELD=fifi
Error: Failed to build or upload nice_nano fifi undefined

https://github.com/hmngwy/zmk/actions/runs/4234720633/jobs/7357427250#step:10:140

I'm not quite sure what I'm doing wrong, I checked the New Keyboard Shields guide as well if anything there is new since I slept on this PR, and it seems what I added here seems to still comply, however the error says otherwise and I can't tell what I'm missing.

If you're not too busy, a quick look would be appreciated. Thanks!

[caksoylar]

@hmngwy You should be building with fifi_left and fifi_right shields separately, right? I.e. you need to add the siblings property in the metadata file, at least.