Nix commands show their man pages as their help, e.g. `nix-shell --help` is equivalent to `man nix-shell`. I think this works well, and reduces the burden of wr

Nix commands show their man pages as their help, e.g. `nix-shell --help` is equivalent to `man nix-shell`. I think this works well, and reduces the burden of writing the same documentation over and over.