[HV] Adding extractors example to README.md
[HV] Adding extractors example to README.md

DavideD/hibernate-demos,DavideD/hibernate-demos,hibernate/hibernate-demos,DavideD/hibernate-demos,DavideD/hibernate-demos,hibernate/hibernate-demos,hibernate/hibernate-demos,hibernate/hibernate-demos,DavideD/hibernate-demos,hibernate/hibernate-demos