Sync web site with Quarkus documentation

Author: quarkusbot

_guides/_attributes.adoc

@@ -1,7 +1,7 @@
 // Common attributes.
 // --> No blank lines (it ends the document header)
 :project-name: Quarkus
-:quarkus-version: 3.19.4
+:quarkus-version: 3.20.0
 :quarkus-platform-groupid: io.quarkus.platform
 // .
 :maven-version: 3.9.9