feat(shield): Add A. Dux shield

[dxmh]

This PR adds a new shield for Architeuthis Dux by Tapi (aka A. Dux, A.D., "Giant squid").

The shield has been available at dxmh/zmk-architeuthis-dux for a couple of months already, but it would be great for Architeuthis Dux to be supported in ZMK properly.

[petejohanson]

A few initial comments, thanks!

[dxmh]

Thanks @petejohanson, I've updated the PR based on your comments. 👍

[caksoylar]

Would it be worth keeping the machine name a_dux similar to the QMK PR? It is pretty subjective, but might be user friendlier.

[petejohanson]

Would it be worth keeping the machine name a_dux similar to the QMK PR? It is pretty subjective, but might be user friendlier.

Given most of the conversations on the LPK have always used the shorthand, and the QMK naming is also doing so, I'm leaning towards agreeing w/ this. And indeed, much easier to type as needed if editing build.yml files, etc.

Thoughts @dxmh?

[dxmh]

Thanks @caksoylar, @petejohanson - using the short name for user-friendliness is an excellent point.

I've just updated the PR so the shield now uses a_dux (and "A. Dux" for consistency).

[petejohanson]

Just one more minor fix found while verifying the metadata work.

Thanks!

[petejohanson]

LGTM!