Support TailwindCSS 1.8.0

[laymonage]

Hi, thanks for the awesome extension!

I'm using the latest version (0.4.3) with TailwindCSS 1.8.6. I'm trying to use the experimental dark mode support introduced in TailwindCSS 1.8.0, but this extension doesn't yet support it. It would be awesome if it does. Thanks!

[bradlc]

Dark mode support was improved in v0.5.0 following the release of Tailwind v2 👍