[boost] Boost.Http parser documentation ready (feedback welcome)

Hi, first of all, do not confuse this “Boost.Http” library with the one who was rejected in the Boost review. I've received financing[1] from Boost to write an HTTP parser and here it is, just a parser. The documentation has 4 tutorials. You may have special interest in the “tutorial #4: implementing Boost.Beast parser interface” where I answer why you don't want to use Boost.Beast parser. https://vinipsmaker.github.io/asiohttpserver/ Feedback welcome. [1] https://gist.github.com/vinipsmaker/4998ccfacb971a0dc1bd -- Vinícius dos Santos Oliveira https://vinipsmaker.github.io/