Merge pull request #256 from modcluster/dependabot/maven/org.asciidoctor-asciidoctorj-pdf-2.3.21

Bump org.asciidoctor:asciidoctorj-pdf from 2.3.20 to 2.3.21

Author: jajik

docs/pom.xml

@@ -16,7 +16,7 @@
 
     <properties>
         <version.asciidoctor-maven-plugin>3.2.0</version.asciidoctor-maven-plugin>
-        <version.org.asciidoctor.asciidoctorj-pdf>2.3.20</version.org.asciidoctor.asciidoctorj-pdf>
+        <version.org.asciidoctor.asciidoctorj-pdf>2.3.21</version.org.asciidoctor.asciidoctorj-pdf>
         <version.org.asciidoctor.asciidoctorj-epub3>2.2.0</version.org.asciidoctor.asciidoctorj-epub3>
     </properties>