add tailscale (and helium?)

modules/features/layers/development.nix

@@ -8,6 +8,10 @@
   flake.nixosModules.development =
     { pkgs, lib, ... }:
     {
+      imports = [
+        self.nixosModules.tailscale
+      ];
+
       config = {
         environment.systemPackages = with pkgs; [
           vim

modules/features/tailscale.nix

@@ -0,0 +1,10 @@
+{ self, inputs, ... }:
+{
+  flake.nixosModules.tailscale =
+    { pkgs, lib, ... }:
+    {
+      config = {
+        services.tailscale.enable = true;
+      };
+    };
+}