Update en/reference/working-with-objects.rst

- change $dm->createQuery(..) to $dm->createQueryBuilder(..)
- add section on querying with $qb->references($document) and $qb->includesReferenceTo($document)
Update en/reference/working-with-objects.rst

made changes requested by @jmikola
Merge pull request #58 from dao/patch-1

Update en/reference/working-with-objects.rst