flake: move options into corresponding files

modules/options/system/programs/default.nix

@@ -3,8 +3,6 @@
 in {
   options.modules.system.programs = {
     editors = {
-      emacs.enable = mkEnableOption "Emacs operatig system";
-      neovim.enable = mkEnableOption "Neovim text editor";
       helix.enable = mkEnableOption "Helix text editor";
       kakoune.enable = mkEnableOption "Kakoune text editor";
     };
@@ -12,13 +10,7 @@ in {
     discord.enable = mkEnableOption "Discord messenger";
     spotify.enable = mkEnableOption "Spotify music client";
     zathura.enable = mkEnableOption "Zathura pdf viewer";
-    nextcloud.enable = mkEnableOption "Nextcloud sync client";
-    firefox.enable = mkEnableOption "Firefox web browser";
-    zellij.enable = mkEnableOption "Zellij terminal multiplexer";
-    steam.enable = mkEnableOption "Steam games platform";
 
-    eza.enable = mkEnableOption "eza";
-    oh-my-posh.enable = mkEnableOption "oh-my-posh";
     nushell.enable = mkEnableOption "nushell";
     terminals = {
       foot.enable = mkEnableOption "Foot terminal emulator";

modules/programs/gui/steam.nix

@@ -4,9 +4,12 @@
   pkgs,
   ...
 }: let
-  inherit (lib) mkIf;
+  inherit (lib.modules) mkIf;
+  inherit (lib.options) mkEnableOption;
+
   cfg = config.modules.system.programs.steam;
 in {
+  options.modules.system.programs.steam.enable = mkEnableOption "Steam games platform";
   config = mkIf cfg.enable {
     programs.steam = {
       enable = true;