refactor: moved modules to legacy-modules

legacy-modules/nixos-modules/tailscale/tailscale.nix

@@ -0,0 +1,19 @@
+{
+  config,
+  lib,
+  ...
+}: {
+  options = {
+    host.tailscale = {
+      enable = lib.mkEnableOption "should tailscale be enabled on this computer";
+    };
+  };
+
+  config = lib.mkIf config.services.tailscale.enable (
+    lib.mkMerge [
+      {
+        # any configs we want shared between all machines
+      }
+    ]
+  );
+}