Document ModelSerializer.create method

[PetrDlouhy]

In the documentation is no mention how to use ModelSerializer for the simple NameserverViewSet, so that the POST method would work and associate the domain_pk field.
I don't know how to use it correctly, but I came up with this (after some time of experimenting):

from rest_framework import serializers
from .models import Nameserver


class NameserverSerializer(serializers.ModelSerializer):

    class Meta:
        model = Nameserver
        fields = [
           ...
        ]

    def create(self, validated_data):
        validated_data['domain_id'] = self.context['view'].kwargs['domain_pk']
        return super().create(validated_data)

[allburov]

Another way to do it in the ViewSet I found here #187 (comment)

class NameserverViewset(viewsets.ModelViewSet):
    (...)
    def perform_create(self, serializer):
        serializer.save(user=self.request.user, domain_id=self.kwargs['domain_pk'])