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.
See https://github.com/browserpass/browserpass-native/issues/31
Additionally browserpass was removed from systemPackages, because it
doesn't need to be installed, browsers will get the path to the binary
from the native messaging host JSON.