This PR adds an example Next.js project with chakra-ui as its component library using TypeScript.
![image](https://user-images.githubusercontent.com/11686408/91192736-a8ec5980-e6cc-11ea-8f95-b9180defbf47.png)
Both libraries has built-in TypeScript declarations. Will help to encourage typed projects, so why not?

It's a combination of two existing examples [with-chakra-ui](https://github.com/vercel/next.js/tree/canary/examples/with-chakra-ui) and [with-typescript](https://github.com/vercel/next.js/tree/canary/examples/with-typescript).

All credits for their contributors.