release-notes: add LXD support

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

@@ -100,6 +100,25 @@
           Notes</link> for details.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          LXD support was greatly improved:
+        </para>
+        <itemizedlist spacing="compact">
+          <listitem>
+            <para>
+              building LXD images from configurations is now directly
+              possible with just nixpkgs
+            </para>
+          </listitem>
+          <listitem>
+            <para>
+              hydra is now building nixOS LXD images that can be used
+              standalone with full nixos-rebuild support
+            </para>
+          </listitem>
+        </itemizedlist>
+      </listitem>
     </itemizedlist>
   </section>
   <section xml:id="sec-release-21.11-new-services">

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

@@ -35,6 +35,10 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - GNOME has been upgraded to 41. Please take a look at their [Release Notes](https://help.gnome.org/misc/release-notes/41.0/) for details.
 
+- LXD support was greatly improved:
+  - building LXD images from configurations is now directly possible with just nixpkgs
+  - hydra is now building nixOS LXD images that can be used standalone with full nixos-rebuild support
+
 ## New Services {#sec-release-21.11-new-services}
 
 - [btrbk](https://digint.ch/btrbk/index.html), a backup tool for btrfs subvolumes, taking advantage of btrfs specific capabilities to create atomic snapshots and transfer them incrementally to your backup locations. Available as [services.btrbk](options.html#opt-services.brtbk.instances).