refactor: don't include the whole modules

Instead only import the nixos/hm/nixvim module.

This _should_ reduce rebuilds.

example-vm/default.nix

@@ -0,0 +1,40 @@
+{
+  imports = [ ./vm-config.nix ];
+
+  time.timeZone = "Europe/Berlin";
+  i18n.defaultLocale = "en_US.UTF-8";
+  users.users.jdoe = {
+    password = "example";
+    isNormalUser = true;
+    extraGroups = [
+      "wheel"
+      "video"
+      "networkmanager"
+    ];
+  };
+  home-manager.users.jdoe = {
+    home = {
+      username = "jdoe";
+      homeDirectory = "/home/jdoe";
+    };
+    jhome = {
+      enable = true;
+      gui.enable = true;
+      dev = {
+        enable = true;
+        rust.enable = true;
+      };
+    };
+  };
+
+  # password is 'test' see module documentation for more options
+  services.jupyter.password = "'sha1:1b961dc713fb:88483270a63e57d18d43cf337e629539de1436ba'";
+  jconfig = {
+    enable = true;
+    dev = {
+      enable = true;
+      jupyter.enable = true;
+    };
+    gui.enable = true;
+  };
+}