Blog about "Fully Pluggable TLSv1.3 Key Exchange"

[romen]

https://github.com/openssl/openssl/pull/11914 added "Fully Pluggable TLSv1.3 Key Exchange" to libssl

@mattcaswell this seems like quite a significant new feature for libssl (I am pretty excited about it and its potential!): should we add a CHANGES and a NEWS entry for it?

Yes - it should have that. I'd actually like to blog about it at some point with some kind of tutorial type approach to explain how to use it.

Originally posted by @mattcaswell in https://github.com/openssl/openssl/pull/11914#issuecomment-650064385

This is a reminder for @mattcaswell , further down when we are approaching the release, as it is a great idea!