feat: improve flake structure

lib/createUser.nix

@@ -0,0 +1,18 @@
+name:
+{ user ? { }, hm ? { }, modules ? [ ], config, ... }:
+
+{ pkgs, lib, home-manager, ... }: {
+  imports = [ home-manager.nixosModules.home-manager ];
+
+  users.users."${name}" = {
+    isNormalUser = true;
+    shell = pkgs.zsh;
+  } // user;
+
+  home-manager = {
+    useUserPackages = true;
+    useGlobalPkgs = true;
+    backupFileExtension = "backup";
+    users."${name}" = lib.mkMerge [ { imports = modules; } (import config) ];
+  } // hm;
+}