Introduces non-server home-manager configs

Allows home-manager configs to be done on a server/non-server basis

Provides an example config by moving emacs to its own space (behind a
lib.optionals so only non-server machines accept it)

marks artemision and rhapsody-in-green as explicitly non-server machines

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

lib/systems.nix

@@ -159,7 +159,9 @@ rec {
     }@args:
     lib.nixosSystem {
       inherit system;
-      specialArgs = inputs;
+      specialArgs = {
+        inherit inputs server;
+      };
       modules =
         [
           inputs.nixos-modules.nixosModule