Update website link

[piotr-yuxuan]

https://github.com/zeit/hyper-website says it's deprecated and redirects to this repository's website/ folder. This PR actually updates website link in readme.md.

As suggested in comments,

• This PR is ready to be merged
• This PR contains a single commit which wraps atomic change: no by-products or side-effects or this repository
• You may be willing to delete the other now-defunct repository or keep it for historical purpose.
• Of course you can rebase it

Cheerio and thanks again for that's an awesome piece of code 😄

[timothyis]

Thanks 👍