Move some (all) files around

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/system/configs/nix/default.nix

@@ -0,0 +1,18 @@
+{ inputs, ... }:
+{
+  nix = {
+    settings = {
+      use-xdg-base-directories = true;
+      experimental-features = [
+        "nix-command"
+        "flakes"
+      ];
+    };
+
+    registry.self.flake = inputs.self;
+    gc.automatic = true;
+    optimise.automatic = true;
+  };
+
+  nixpkgs.config.allowUnfree = true;
+}