[Docs] Button, ButtonBase, Checkbox, TextButton migration documentation

[georgewrmarshall]

Summary

Add migration documentation for Button-related components and form components that have been migrated from Extension to MMDS.

Components

• Button
• ButtonBase
• Checkbox
• TextButton

Note: ButtonPrimary, ButtonSecondary, ButtonLink are variants of Button and covered by the same migration docs.

Definition of Done

1. MIGRATION.md Sections

Add migration sections with API maps to:

• packages/design-system-react/MIGRATION.md
• packages/design-system-react-native/MIGRATION.md (if applicable)

Include:

• Breaking changes between Extension/Mobile and MMDS
• Prop mapping tables (size, variant enums, etc.)
• Before/after code examples

2. README Links

Add migration section to each component's README.mdx:

• Link to relevant MIGRATION.md section

3. @deprecated Updates

Add migration links to JSDoc in:

• Extension: ui/components/component-library/button*, checkbox*, text-button*
• Mobile: Check if similar components exist

Example Reference

ButtonIcon version migration: https://github.com/MetaMask/metamask-design-system/blob/main/packages/design-system-react/MIGRATION.md#buttonicon-variant-prop

Labels

documentation