[docs] Buttons

[m-bert]

Description

This PR updates Buttons entry in docs.

Test plan

Read docs 🤓

[Copilot]

Pull request overview

Updates Gesture Handler 3 migration and documentation content around button components, including a rewrite of the Buttons docs page and additional notes in the GH3 upgrade guide.

Changes:

• Reworked buttons.mdx content/structure (added RawButton, reorganized props, moved accessibility section).
• Updated “Upgrading to 3” guide and migration skill docs with notes about legacy buttons / PureNativeButton.
• Minor formatting adjustments (spacing) in the GH3 migration skill doc.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 6 comments.

File	Description
skills/gesture-handler-3-migration/SKILL.md	Adds migration guidance around buttons and mentions PureNativeButton.
packages/docs-gesture-handler/docs/guides/upgrading-to-3.mdx	Updates upgrade guidance and legacy buttons mapping table.
packages/docs-gesture-handler/docs/components/buttons.mdx	Major rewrite/restructure of the Buttons documentation page.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[akwasniewski]

We probably want to suggest possible solutions it can propose to the user

[m-bert]

I think it depends on their use case. Using PureNativeButton should be rare case anyway and I'm not sure if simply saying "change it to RawButton" will work, as it has Native gesture pre-applied. So I'm not sure if there's a panacea for that specific case. cc @j-piasecki

[j-piasecki]

I'm not sure there is a clear migration path here - I think the only use case for PureNativeButton was to pass it into createAnimatedComponent and wrap with a native gesture later. createAnimatedComponent now won't work with the new implementation due to the "sandwich" structure of the new button, so this use case is gone.

You'd most likely need to wrap the button with a view and animate that, while having the button styled in a way to adapt to the view changes. We could add that to the skill, with some note that the agent should ask or at least inform the user that it needs double checking.