This aids in making it more uniform in style with most manuals on *nix
systems in terms of formatting. Plus, the semantic markup will make it
easier to maintain and less reliant on writing for the renderer.
Previously, the manpage listed every flag and parameter as optional, implying
that they could be used in any combination, which isn't true. As a trivial
example, to use Kakoune in "list sessions" mode, you *must* specify -l, and you
*must not* specify any other options. To use Kakoune in any other mode, you
*must not* specify -l.
