yambar: document breaking changes

* Previously, both the xorg and wayland backend were built into the yambar
  package. The refactor breaks up each backends to its separate, with xorg
  being the default. Thus yambar users on wayland should switch to the
  yambar-wayland package.

nixos/doc/manual/from_md/release-notes/rl-2111.section.xml

@@ -663,6 +663,15 @@
           group.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          The <literal>yambar</literal> package has been split into
+          <literal>yambar</literal> and
+          <literal>yambar-wayland</literal>, corresponding to the xorg
+          and wayland backend respectively. Please switch to
+          <literal>yambar-wayland</literal> if you are on wayland.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
   <section xml:id="sec-release-21.11-notable-changes">

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

@@ -166,6 +166,8 @@ pt-services.clipcat.enable).
 
 - The `openrazer` and `openrazer-daemon` packages as well as the `hardware.openrazer` module now require users to be members of the `openrazer` group instead of `plugdev`. With this change, users no longer need be granted the entire set of `plugdev` group permissions, which can include permissions other than those required by `openrazer`. This is desirable from a security point of view. The setting [`harware.openrazer.users`](options.html#opt-services.hardware.openrazer.users) can be used to add users to the `openrazer` group.
 
+- The `yambar` package has been split into `yambar` and `yambar-wayland`, corresponding to the xorg and wayland backend respectively. Please switch to `yambar-wayland` if you are on wayland.
+
 ## Other Notable Changes {#sec-release-21.11-notable-changes}
 
 - The setting [`services.openssh.logLevel`](options.html#opt-services.openssh.logLevel) `"VERBOSE"` `"INFO"`. This brings NixOS in line with upstream and other Linux distributions, and reduces log spam on servers due to bruteforcing botnets.