`@theme-ui/editor doesn'`t use `@theme-ui/components`

[jordanoverbye]

We use both @theme-ui/editor and @theme-ui/editor for the side panel. They have different styles at the moment which could should be able to be fixed easily by adding styles to theme.js.

The problem is, @theme-ui/editor doesn't use @theme-ui/components so the styles aren't getting applied.

I'm working on fixing this in theme-ui, then I should be able to clean up the styles for inputs/selects etc so they all look the same and come from theme.js

Issue system-ui/theme-ui#608