move options back out to their config files, improve documentation

modules/features/hardware/steam-controller.nix

@@ -1,4 +1,8 @@
 { inputs, self, ... }: {
+  imports = [ (inputs.helpers.mkMirroredModulesFlakeModule "gamingOptions" ({ lib, ... }: {
+    options.features.hardware.steam-controller.enable = lib.mkEnableOption "tweaks and configurations that assist when using Valve's Steam Controller";
+  })) ];
+
   flake.nixosModules.gaming = { pkgs, config, lib, ... }: {
     config = lib.mkIf (config.features.hardware.steam-controller.enable) {
       home-manager.users.grey = lib.mkIf (config.features.nixos.home-manager.enable) {