Autogenerate POM for Github "Used by"

The library used in this repository is not linked in the Github "Used by", because Gradle it is not supported yet.

I found a workaround some time ago, described [in this post](https://stackoverflow.com/questions/57903806/adding-used-by-inside-the-github-project-with-gradle-and-java) the only thing to do is adding the autogeneration of `pom.xml` file in the Gradle file.