chore(users): grfn -> aspen

Change-Id: I6c6847fac56f0a9a1a2209792e00a3aec5e672b9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10809
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: lukegb <lukegb@tvl.fyi>

users/aspen/system/home/home.nix

@@ -0,0 +1,20 @@
+{ config, pkgs, ... }:
+
+{
+  imports = [
+    (throw "Pick a machine from ./machines")
+  ];
+
+  # Let Home Manager install and manage itself.
+  programs.home-manager.enable = true;
+
+  # This value determines the Home Manager release that your
+  # configuration is compatible with. This helps avoid breakage
+  # when a new Home Manager release introduces backwards
+  # incompatible changes.
+  #
+  # You can update Home Manager without changing this value. See
+  # the Home Manager release notes for a list of state version
+  # changes in each release.
+  home.stateVersion = "19.09";
+}