pedantic doc updates

docs/api-guide/viewsets.md

@@ -98,6 +98,7 @@ For example:
 
     from django.contrib.auth.models import User
     from rest_framework import viewsets
+    from rest_framework import status
     from rest_framework.decorators import action
     from rest_framework.response import Response
     from myapp.serializers import UserSerializer, PasswordSerializer