feat(nixos): improve editor and shell service configuration

- Replace `vim.defaultEditor` with `neovim.defaultEditor`.
- Add `vim.enable` to enable Vim by default.
- Simplify imports by removing unused `options`.

modules/nixos/services/base/default.nix

@@ -1,9 +1,7 @@
-{
-  options,
-  config,
-  lib,
-  pkgs,
-  ...
+{ config
+, lib
+, pkgs
+, ...
 }:
 with lib;
 with lib.metacfg;
@@ -108,9 +106,10 @@ in
       };
       starship.enable = true;
       mosh.enable = true;
-      vim = {
-        defaultEditor = true;
+      vim.enable = true;
+      neovim = {
         enable = true;
+        defaultEditor = true;
       };
       fish.enable = true;
     };