Promote release candidate to v4

[TutorLatin]

Hi @jonasgeiler

It looks like v4.0.0-rc.1 has been stable for a while.

Unless there are any known issues, should we go ahead and promote it to a stable v4.0.0 release?

I've been running it in production for about 3 weeks without problems.

Happy to help if needed!

[brunocalou]

I've just installed the v4.0.0-rc.1 version and the typing is incorrect. The header and footer are marked as required, but they're clearly optional. Also, children as any is not good.

[jonasgeiler]

I did notice a few problems - among others with the typings, as @brunocalou pointed out - which I'd like fixed before we go stable.
Unfortunately I'm currently on vacation with no access to my laptop until the 13th of August. Afterwards I'll look into releasing v4!