refactor: don't include the whole modules

Instead only import the nixos/hm/nixvim module.

This _should_ reduce rebuilds.

example-vm/vm-config.nix

@@ -0,0 +1,34 @@
+## Default QEMU guest config
+{
+  services = {
+    qemuGuest.enable = true;
+    openssh.enable = true;
+  };
+
+  boot = {
+    loader.systemd-boot.enable = true;
+    initrd.availableKernelModules = [
+      "xhci_pci"
+      "ehci_pci"
+      "ahci"
+      "usbhid"
+      "usb_storage"
+      "sd_mod"
+      "virtio_balloon"
+      "virtio_blk"
+      "virtio_pci"
+      "virtio_ring"
+      # "virtio_vga"
+      "virtio_gpu"
+    ];
+  };
+  fileSystems."/".device = "/dev/disk/by-label/nixos";
+
+  # This value determines the NixOS release from which the default
+  # settings for stateful data, like file locations and database versions
+  # on your system were taken. It‘s perfectly fine and recommended to leave
+  # this value at the release version of the first install of this system.
+  # Before changing this value read the documentation for this option
+  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
+  system.stateVersion = "24.11"; # Did you read the comment?
+}