feat: redesign the project structure

modules/nixos/user_group.nix

@@ -0,0 +1,18 @@
+{config, pkgs, ...}:
+
+{
+  users.groups = {
+    ryan = {};
+    docker = {};
+    wireshark = {};
+  };
+  # Define a user account. Don't forget to set a password with ‘passwd’.
+  users.users.ryan = {
+    isNormalUser = true;
+    description = "ryan";
+    extraGroups = [ "ryan" "users" "networkmanager" "wheel" "docker" "wireshark" "adbusers" ];
+    openssh.authorizedKeys.keys = [
+        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJx3Sk20pLL1b2PPKZey2oTyioODrErq83xG78YpFBoj"
+    ];
+  };
+}