refactor(docker): move the docker group to the respective nix module instead of adding the user per default

modules/nixos/docker.nix

@@ -1,6 +1,9 @@
 { config, lib, pkgs, ...}:
 
 {
+  # add docker group to user
+  users.users.aaron.extraGroups = [ "docker" ];
+
   virtualisation.docker = {
     enable = true;
     # Customize Docker daemon settings

modules/nixos/users.nix

@@ -5,7 +5,7 @@
   users.users.aaron = {
     isNormalUser = true;
     group = "users";
-    extraGroups = [ "wheel" "networkmanager" "docker" ];
+    extraGroups = [ "wheel" "networkmanager" ];
     shell = pkgs.zsh;
   };