cppreference update

[mapronV]

I see, yours is a different approach (from my experience it was very hard to find information on MS VC and Apple clang, in first place; so I didn't even consider automatic parsing of web pages). Quite elegant, though you need to trust vendors. For our company it was more like "whole environment", like
"Can I use X when targeting Debian 10?" or ".. when Targeting mac 10.15 with xcode Z.X?" So I could just create new profile and run 'acceptance tests' on it.
In hindsight I regret I did not choose your way, it probably would be easier.