fix(website): refine landing page button feedback and links

[NicooleT]

Changes

The landing-page copy button now grows to 1.15× on hover, and Get started and Example app shrink to 0.96× while pressed with a 150ms transition, matching react-native-ease. The blue button hover fill is limited to devices with hover and a fine pointer. Remove all landing-page ↗ link arrows and the GitHub icon from Example app.

Verification

• Passed formatting, lint, TypeScript checks, all 8 Jest tests, library build, and documentation build.
• Packed and validated the npm tarball: 34 package files verified.
• Inspected the production preview at desktop and 390px mobile widths and confirmed both button destinations.
• Native builds are not applicable to this website-only change.

Known limitations

• Hover/press animation playback and physical touch-device behavior have not been verified interactively.
• The copy button's later transition declaration overrides its reduced-motion transition rule. A proposed specificity correction remains pending user approval and is not included in this approved patch.
• Screenshots were inspected in the local review but are not attached to this PR.