add shell.nix

[milahu]

in my case:
nix develop will download 2GB of dependencies = killjoy
nix-shell will download 10MB of dependencies

can we add a shell.nix file? (and call that from flake.nix)

{ pkgs ? import <nixpkgs> {} }:
pkgs.mkShell {
  buildInputs = with pkgs; [
    cargo
    cargo-tarpaulin
    clippy
    entr
    jq
    linuxPackages_latest.perf
    reuse
    rustc
  ];
}

[kamadorueda]

That's ok, sure