This project does not use anything useful, however it is a valid project, that can be used as an example for releases to Wildfly Extras repository (https://repository.jboss.org/nexus/content/repositories/wildfly-extras/)
You can find more information about publishing of Wildfly Extras artifacts in this article:
https://developer.jboss.org/docs/DOC-52892
Note: The example has all required sections to be able to publish WildFly Extras, however consider using parent pom https://github.com/jboss/jboss-parent-pom as a good practice.