most of these are hidden because they're either part of a submodule that
doesn't have its type rendered (eg because the submodule type is used in
an either type) or because they are explicitly hidden. some of them are
merely hidden from nix-doc-munge by how their option is put together.
conversions were done using https://github.com/pennae/nix-doc-munge
using (probably) rev f34e145 running
nix-doc-munge nixos/**/*.nix
nix-doc-munge --import nixos/**/*.nix
the tool ensures that only changes that could affect the generated
manual *but don't* are committed, other changes require manual review
and are discarded.
markdown can't represent the difference without another extension and
both the html manual and the manpage render them the same, so keeping the
distinction is not very useful on its own. with the distinction removed
we can automatically convert many options that use <code> tags to markdown.
the manpage remains unchanged, html manual does not render
differently (but class names on code tags do change from "code" to "literal").
