Add Apple HIG Skills

[zacharyr0th]

Hi! I'd like to suggest adding Apple HIG Skills to this collection.

What it is: 14 agent skills providing Apple Human Interface Guidelines for iOS, macOS, visionOS, watchOS, and tvOS design decisions. Covers platforms, foundations, components (layout, controls, dialogs, menus, search, status, system, content), patterns, inputs, and technologies.

Built on: the agentskills.io spec

Repo: https://github.com/raintree-technology/apple-hig-skills

Happy to submit a PR if that's preferred!

[aaronpowell]

For something to be available through this repo (or though a plugin in the repo) it does need to be contributed, so if you're happy to contribute it, we'd be happy to have it 😊