Please extend example with NameserverViewSet

Thank you for coding this useful thing. I have a suggestion because I faced a problem while experimenting with your app.

Please consider extending example by providing NameserverViewSet code to make clear how {pk} and domain {domain_pk} should be used in ViewSets.
General example of ViewSet is below, but how to enable filtering by {domain_pk} is not clear, so I have all Nameserver objects listed.

class NameserverViewSet(viewsets.ModelViewSet):
    queryset = Nameserver.objects.all()
    serializer_class = NameserverSerializer

[alanjds]

@artem-fedosov & @cameronblandford: The updated README from #108 does suits your needs? Can I close the issue here?

[alanjds]

Will close for now. Can be reopened.