Migrate UI components to `@primer/components`

[JasonEtco]

The Primer team is working on a React-Primer library, and since we're using Primer and React, we should be using this! Its currently in beta, but we can try it out and give feedback where we can.

https://primer.github.io/primer-react/components

[shawnbot]

Yaaaaas! Let us know how we can help! 🎉

[stale]

Is this still relevant? If so, what is blocking it? Is there anything you can do to help move it forward?

[JasonEtco]

Thanks for the reminder ❤️ We'd still like to do this, when time permits!

[shawnbot]

FYI, it's now called @primer/components 😄

[wolfy1339]

Needs to be moved to probot/smee.io

[JasonEtco]

Yep, was literally about to do all of those, thanks for the callout @wolfy1339!