nixos/mullvad-vpn: add cross-platform availability announcement to release notes

nixos/doc/manual/from_md/release-notes/rl-2211.section.xml

@@ -1102,6 +1102,18 @@
           <literal>services.wordpress.sites.&lt;site&gt;.languages</literal>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          The default package for
+          <literal>services.mullvad-vpn.package</literal> was changed to
+          <literal>pkgs.mullvad</literal>, allowing cross-platform usage
+          of Mullvad. <literal>pkgs.mullvad</literal> only contains the
+          Mullvad CLI tool, so users who rely on the Mullvad GUI will
+          want to change it back to <literal>pkgs.mullvad-vpn</literal>,
+          or add <literal>pkgs.mullvad-vpn</literal> to their
+          environment.
+        </para>
+      </listitem>
       <listitem>
         <para>
           There is a new module for the <literal>thunar</literal>

nixos/doc/manual/release-notes/rl-2211.section.md

@@ -342,6 +342,8 @@ Available as [services.patroni](options.html#opt-services.patroni.enable).
 
 - The Wordpress module got support for installing language packs through `services.wordpress.sites.<site>.languages`.
 
+- The default package for `services.mullvad-vpn.package` was changed to `pkgs.mullvad`, allowing cross-platform usage of Mullvad. `pkgs.mullvad` only contains the Mullvad CLI tool, so users who rely on the Mullvad GUI will want to change it back to `pkgs.mullvad-vpn`, or add `pkgs.mullvad-vpn` to their environment.
+
 - There is a new module for the `thunar` program (the Xfce file manager), which depends on the `xfconf` dbus service, and also has a dbus service and a systemd unit. The option `services.xserver.desktopManager.xfce.thunarPlugins` has been renamed to `programs.thunar.plugins`, and in a future release it may be removed.
 
 - There is a new module for the `xfconf` program (the Xfce configuration storage system), which has a dbus service.