news: add zsh dotDir default change

Default has changed to respect `xdg.enable`. Let user's know in case it
affects them surprisingly.

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

modules/misc/news/2025/12/2025-12-27_13-32-14.nix

@@ -0,0 +1,20 @@
+{ config, ... }:
+{
+  time = "2025-12-27T19:00:00+00:00";
+  condition = config.programs.zsh.enable;
+
+  message = ''
+    The default value of `programs.zsh.dotDir` has changed.
+
+    When `home.stateVersion` is set to "26.05" or later, and `xdg.enable` is
+    `true` (the default), `programs.zsh.dotDir` now defaults to
+    `''${config.xdg.configHome}/zsh`. Previously, it defaulted to the home
+    directory.
+
+    This means your Zsh configuration files (`.zshrc`, `.zshenv`, etc.) will be
+    moved to `~/.config/zsh` (or your configured XDG config home).
+
+    If you prefer the old behavior, you can explicitly set:
+    `programs.zsh.dotDir = config.home.homeDirectory;`
+  '';
+}