message: Update primer css link
diff: @@ -40,4 +40,4 @@ export default () => (
  This will set the `color`, `font-family`, and `line-height` CSS properties to the same ones used in [Primer CSS](https://github.com/primer/css/blob/master/src/base/base.scss#L15-L21).
  -[Primer CSS]: https://github.com/primer/primer
  +[Primer CSS]: https://github.com/primer/css
  