nixos/doc: Plasma wayland changelog

nixos/doc/manual/release-notes/rl-2111.section.md

@@ -18,6 +18,9 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - Activation scripts can now opt int to be run when running `nixos-rebuild dry-activate` and detect the dry activation by reading `$NIXOS_ACTION`.
   This allows activation scripts to output what they would change if the activation was really run.
+
+- We can now finally use Plasma on Wayland.
+
   The users/modules activation script supports this and outputs some of is actions.
 
 - bash now defaults to major version 5.
@@ -342,6 +345,7 @@ In addition to numerous new and upgraded packages, this release has the followin
   configuration file. For details, see the [upstream changelog](https://github.com/DataDog/datadog-agent/blob/main/CHANGELOG.rst).
 
 - `opencv2` no longer includes the non-free libraries by default, and consequently `pfstools` no longer includes OpenCV support by default.  Both packages now support an `enableUnfree` option to re-enable this functionality.
+- `services.xserver.displayManager.defaultSession = "plasma5"` does not work anymore, instead use either `"plasma"` for the Plasma X11 session or `"plasmawayland"` for the Plasma Wayland sesison.
 
 ## Other Notable Changes {#sec-release-21.11-notable-changes}