Switched nixos config to allow for shared configuration files

nixos/core.nix

@@ -0,0 +1,13 @@
+{
+  inputs,
+  outputs,
+  lib,
+  config,
+  pkgs,
+  unstablePkgs,
+  ...
+}: {
+  imports = [
+    ./core/programs.nix
+  ];
+}