NixOS installation instructions are wrong.

[con-f-use]

The instructions of NixOS without flake are wrong:

https://github.com/snowfallorg/nixos-conf-editor/tree/27b5e92f580f794c690093503869aab242f075ab?tab=readme-ov-file#nixos-installation

Following them gives error: attempt to call something which is not a function.

They should probably read something like this:

{ config, pkgs, lib, ... }:
let
  nixos-conf-editor-flake = import (pkgs.fetchFromGitHub {
    owner = "snowfallorg";
    repo = "nixos-conf-editor";
    rev = "0.1.2";
    sha256 = "sha256-/ktLbmF1pU3vFHeGooDYswJipNE2YINm0WpF9Wd1gw8=";
  });
in
#...
environment.systemPackages = with pkgs; [
  nixos-conf-editor-flake.packages.${system}.nixos-conf-editor
];

i.e. not calling the import and using the proper flake output. Or you have to change your default.nix.