remove docker section; it's already showed off in the contrib page

remove paragraph "locally installed libressl" + some tweaks libtls is now widely available, it's at least on gentoo, arch, void, alpine, fedora and debian sid; there's no need to show how to compile to a locally installed one.

mention the reverse proxying

don't list the exact pledge promises It's easy to forgot to update the README after a code change (already happened in the past) and they're easy to discover by reading sandbox.c

mention landlock in the README

gmid.1: document logging

point to contrib.html

sync with sandbox.c

show macro usage in the example

drop the dependency on lex by implementing yylex by ourselves The actual implementation is based off doas' parse.y. This gave us various benefits, like cleaner code, \ to break long lines, better handling of quotes etc...

mention FastCGI in the

reword last sentence

improve docker example

typo in docker example

typo (again)