Move files into a sub folder to clean up a bit

nix-configs/unstable.nix

@@ -0,0 +1,14 @@
+{ config, pkgs, ...}:
+
+let
+  unstable = import
+    (builtins.fetchTarball https://github.com/nixos/nixpkgs/tarball/master)
+    # reuse the current configuration
+    { config = config.nixpkgs.config; };
+in
+{
+  environment.systemPackages = with pkgs; [
+    unstable.protonvpn-cli
+    unstable.protonvpn-gui
+  ];
+}