nix: Use hosts directory

This may be useful if I want to try NixOS on another host in the future.

flake.nix

@@ -20,7 +20,6 @@
         stylix.nixosModules.stylix
         nix-gaming.nixosModules.pipewireLowLatency
         ./src/main.nix
-        ./hardware-configuration.nix
       ];
     };
   };

src/main.nix

@@ -8,6 +8,7 @@
   VARIABLES = import ./variables.nix;
 in {
   imports = [
+    "${VARIABLES.hostHardwareConfiguration}"
     ../modules
     ../containers/rar.nix
     ../containers/wine.nix

src/variables.nix

@@ -2,4 +2,5 @@
   hostname = "nixos";
   system = "x86_64-linux";
   timezone = "America/New_York";
+  hostHardwareConfiguration = ../hosts/laptop.nix;
 }