Added a flake

[deephack1982]

Added a flake for both build and devshell purposes.

To build
nix build

To get the devshell
nix develop

If you would like to add this to your nixos configuration then you can do the following.

inputs = {
    lag.url = "github:deephack1982/cli";

## more inputs
};

environment.systemPackages = with pkgs; [
  inputs.lag.packages.${pkgs.stdenv.hostPlatform.system}.default
]

[mooncitizen]

This doesnt require a release as its development helper

Approved 👍