Update `@create-figma-plugin/ui` to UI3

[yuanqing]

• UI3 will likely be a major version bump to v4
• Framework consumers will have to use v3 if they want to use the old UI

[ben-katz]

Hi @yuanqing! I am new to open source contribution so apologies if this is a silly question - but is there any way we can help contribute to this issue? I am not sure where to start - do we know if Figma has made UI3 components publicly available, or would it involve us custom coding to match their new changes?

[yuanqing]

The components in Create Figma Plugin are entirely custom. The work would involve manually tweaking every single component in the library to match UI3

[isBatak]

There is now the official Figma UI3 kit https://www.figma.com/community/file/1486123838948777078

[yuanqing]

UI3 is supported as of v4