Extend documentation for NextJS

[hmontazeri]

With the existing functions it should be possible to add this library easily to Nextjs. BC I need it 😅 and probably many do. I’ll try to do it in the coming days, maybe someone’s quicker 🚀

[kentcdodds]

I'm sure it's possible, but I don't personally have time to work on it. Happy to merge a PR that adds utilities for Next.js though