nixos/x11: move extraLayouts into xkb attrset

[Motivation](NixOS#257817 (comment))

`extraLayouts` was missed in #259891, so moving it to the other xkb
options with this PR.

Signed-off-by: Paul Meyer <49727155+katexochen@users.noreply.github.com>

nixos/doc/manual/configuration/x-windows.chapter.md

@@ -208,7 +208,7 @@ qt.style = "gtk2";
 
 It is possible to install custom [ XKB
 ](https://en.wikipedia.org/wiki/X_keyboard_extension) keyboard layouts
-using the option `services.xserver.extraLayouts`.
+using the option `services.xserver.xkb.extraLayouts`.
 
 As a first example, we are going to create a layout based on the basic
 US layout, with an additional layer to type some greek symbols by
@@ -235,7 +235,7 @@ xkb_symbols "us-greek"
 A minimal layout specification must include the following:
 
 ```nix
-services.xserver.extraLayouts.us-greek = {
+services.xserver.xkb.extraLayouts.us-greek = {
   description = "US layout with alt-gr greek";
   languages   = [ "eng" ];
   symbolsFile = /yourpath/symbols/us-greek;
@@ -298,7 +298,7 @@ xkb_symbols "media"
 As before, to install the layout do
 
 ```nix
-services.xserver.extraLayouts.media = {
+services.xserver.xkb.extraLayouts.media = {
   description  = "Multimedia keys remapping";
   languages    = [ "eng" ];
   symbolsFile  = /path/to/media-key;

nixos/doc/manual/release-notes/rl-2311.section.md

@@ -318,7 +318,7 @@
   order, or relying on `mkBefore` and `mkAfter`, but may impact users calling
   `mkOrder n` with n ≤ 400.
 
-- X keyboard extension (XKB) options have been reorganized into a single attribute set, `services.xserver.xkb`. Specifically, `services.xserver.layout` is now `services.xserver.xkb.layout`, `services.xserver.xkbModel` is now `services.xserver.xkb.model`, `services.xserver.xkbOptions` is now `services.xserver.xkb.options`, `services.xserver.xkbVariant` is now `services.xserver.xkb.variant`, and `services.xserver.xkbDir` is now `services.xserver.xkb.dir`.
+- X keyboard extension (XKB) options have been reorganized into a single attribute set, `services.xserver.xkb`. Specifically, `services.xserver.layout` is now `services.xserver.xkb.layout`, `services.xserver.extraLayouts` is now `services.xserver.xkb.extraLayouts`, `services.xserver.xkbModel` is now `services.xserver.xkb.model`, `services.xserver.xkbOptions` is now `services.xserver.xkb.options`, `services.xserver.xkbVariant` is now `services.xserver.xkb.variant`, and `services.xserver.xkbDir` is now `services.xserver.xkb.dir`.
 
 - `networking.networkmanager.firewallBackend` was removed as NixOS is now using iptables-nftables-compat even when using iptables, therefore Networkmanager now uses the nftables backend unconditionally.
 

nixos/modules/services/x11/extra-layouts.nix

@@ -3,7 +3,7 @@
 with lib;
 
 let
-  layouts = config.services.xserver.extraLayouts;
+  layouts = config.services.xserver.xkb.extraLayouts;
 
   layoutOpts = {
     options = {
@@ -15,10 +15,10 @@ let
       languages = mkOption {
         type = types.listOf types.str;
         description =
-        lib.mdDoc ''
-          A list of languages provided by the layout.
-          (Use ISO 639-2 codes, for example: "eng" for english)
-        '';
+          lib.mdDoc ''
+            A list of languages provided by the layout.
+            (Use ISO 639-2 codes, for example: "eng" for english)
+          '';
       };
 
       compatFile = mkOption {
@@ -80,29 +80,37 @@ let
   };
 
   xkb_patched = pkgs.xorg.xkeyboardconfig_custom {
-    layouts = config.services.xserver.extraLayouts;
+    layouts = config.services.xserver.xkb.extraLayouts;
   };
 
 in
 
 {
 
+  imports = [
+    (lib.mkRenamedOptionModuleWith {
+      sinceRelease = 2311;
+      from = [ "services" "xserver" "extraLayouts" ];
+      to = [ "services" "xserver" "xkb" "extraLayouts" ];
+    })
+  ];
+
   ###### interface
 
-  options.services.xserver = {
+  options.services.xserver.xkb = {
     extraLayouts = mkOption {
       type = types.attrsOf (types.submodule layoutOpts);
-      default = {};
+      default = { };
       example = literalExpression
-      ''
-        {
-          mine = {
-            description = "My custom xkb layout.";
-            languages = [ "eng" ];
-            symbolsFile = /path/to/my/layout;
-          };
-        }
-      '';
+        ''
+          {
+            mine = {
+              description = "My custom xkb layout.";
+              languages = [ "eng" ];
+              symbolsFile = /path/to/my/layout;
+            };
+          }
+        '';
       description = lib.mdDoc ''
         Extra custom layouts that will be included in the xkb configuration.
         Information on how to create a new layout can be found here:

nixos/tests/keymap.nix

@@ -213,7 +213,7 @@ in pkgs.lib.mapAttrs mkKeyboardTest {
 
     extraConfig.console.useXkbConfig = true;
     extraConfig.services.xserver.xkb.layout = "us-greek";
-    extraConfig.services.xserver.extraLayouts.us-greek =
+    extraConfig.services.xserver.xkb.extraLayouts.us-greek =
       { description = "US layout with alt-gr greek";
         languages   = [ "eng" ];
         symbolsFile = pkgs.writeText "us-greek" ''