add release notes for 22.05 and update codename

lib/trivial.nix

@@ -171,7 +171,7 @@ rec {
      On each release the first letter is bumped and a new animal is chosen
      starting with that new letter.
   */
-  codeName = "Porcupine";
+  codeName = "Quokka";
 
   /* Returns the current nixpkgs version suffix as string. */
   versionSuffix =

nixos/doc/manual/release-notes/rl-2205.section.md

@@ -0,0 +1,13 @@
+# Release 22.05 (“Quokka”, 2022.05/??) {#sec-release-22.05}
+
+In addition to numerous new and upgraded packages, this release has the following highlights:
+
+- Support is planned until the end of December 2022, handing over to 22.11.
+
+## Highlights {#sec-release-22.05-highlights}
+
+## New Services {#sec-release-22.05-new-services}
+
+## Backward Incompatibilities {#sec-release-22.05-incompatibilities}
+
+## Other Notable Changes {#sec-release-22.05-notable-changes}