Stuff for v8.0.1

- [x] Update playground
- [x] Switch Netlify
- [x] Update StackBlitz demo
- [x] Docs need to reference fakerjs.dev instead of next.fakerjs.dev
- [x] Improve v8.0.0 release with some notes about breaking changes and link to upgrading guide
- [x] Clean README.md (in v8 branch)
