cups-pdf: mention new package/module in 23.05 release notes

nixos/doc/manual/from_md/release-notes/rl-2305.section.xml

@@ -30,6 +30,15 @@
           <link linkend="opt-programs.bash.blesh.enable">programs.bash.blesh</link>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <link xlink:href="https://github.com/alexivkin/CUPS-PDF-to-PDF">cups-pdf-to-pdf</link>,
+          a pdf-generating cups backend based on
+          <link xlink:href="https://www.cups-pdf.de/">cups-pdf</link>.
+          Available as
+          <link linkend="opt-services.printing.cups-pdf.enable">services.printing.cups-pdf</link>.
+        </para>
+      </listitem>
       <listitem>
         <para>
           <link xlink:href="https://github.com/junegunn/fzf">fzf</link>,

nixos/doc/manual/release-notes/rl-2305.section.md

@@ -16,6 +16,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - [blesh](https://github.com/akinomyoga/ble.sh), a line editor written in pure bash. Available as [programs.bash.blesh](#opt-programs.bash.blesh.enable).
 
+- [cups-pdf-to-pdf](https://github.com/alexivkin/CUPS-PDF-to-PDF), a pdf-generating cups backend based on [cups-pdf](https://www.cups-pdf.de/). Available as [services.printing.cups-pdf](#opt-services.printing.cups-pdf.enable).
+
 - [fzf](https://github.com/junegunn/fzf), a command line fuzzyfinder. Available as [programs.fzf](#opt-programs.fzf.fuzzyCompletion).
 
 ## Backward Incompatibilities {#sec-release-23.05-incompatibilities}