##### SUMMARY
We should document that by default we go only over first level attributes, not any other level of attribute and maybe ADD parameter which enables going deeper.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
ansible/lib/ansible/modules/cloud/ovirt/*_facts.py

##### ADDITIONAL INFORMATION
Discussion was originally raised in https://bugzilla.redhat.com/show_bug.cgi?id=1653743
class ModuleDocFragment(object):
    
    DOCUMENTATION = r'''
options:
    fetch_nested:
        description:
            - If I(yes) the module will fetch additional data from the API.
            - It will fetch IDs of the VMs disks, snapshots, etc. User can configure to fetch other
              attributes of the nested entities by specifying C(nested_attributes).
        type: bool
        version_added: "2.3"
    nested_attributes:
        description:
            - Specifies list of the attributes which should be fetched from the API.
            - This parameter apply only when C(fetch_nested) is I(true).
        type: list
        version_added: "2.3"
    auth:
        description:
            - "Dictionary with values needed to create HTTP/HTTPS connection to oVirt:"