Update instructions for Haskell script using nix-shell interpreter
Update instructions for Haskell script using nix-shell interpreter

- The instructions for using nix-shell as an interpreter has a Haskell script
  example that doesn't work on more recent versions of Nix. Update the
  instructions with a working command

ehmry/nix,pikajude/nix,dtzWill/nix,dtzWill/nix,ehmry/nix,dtzWill/nix,NixOS/nix,zimbatm/nix,vcunat/nix,rycee/nix,NixOS/nix,rycee/nix,vcunat/nix,ehmry/nix,NixOS/nix,zimbatm/nix,rycee/nix,zimbatm/nix,ehmry/nix,vcunat/nix,ehmry/nix,vcunat/nix,dtzWill/nix,pikajude/nix,dtzWill/nix,zimbatm/nix,rycee/nix,NixOS/nix,ehmry/nix,NixOS/nix,pikajude/nix,rycee/nix