feat: Added vagrant module.

nixosModules/vagrant.nix

@@ -0,0 +1,25 @@
+{ config, ... }: {
+  config = {
+    virtualisation.virtualbox.guest.enable = true;
+
+    # Mount a VirtualBox shared folder.
+    fileSystems."/vagrant" = {
+      fsType = "vboxsf";
+      device = "vagrant";
+      options = [ "rw,uid=1001,gid=60,_netdev" ]; # mount as vagrant:nginx
+    };
+
+    users.users.root.password = "vagrant";
+    users.users."vagrant" = {
+      isNormalUser = true;
+      password = "vagrant";
+      extraGroups = [
+        "nginx"
+        "wheel"
+        # Allow mounting of shared folders.
+        "vboxsf"
+      ];
+    };
+
+    services.openssh.enable = true;
+  }