title: Adding IsAuthenticatedOrReadOnly permission in django rest framework
body: <p>Suppose I have the following model -</p>
  <pre><code>class Person(models.Model):
      name = models.CharField(max_length=200)
      clubs = models.ManyToManyField(Club,related_name = 'people')
      date = models.DateTimeField(default=datetime.now)
      
      def __str__(self):
          return self.name
  </code></pre>
  <p>used to create a rest api.</p>
  <p><code>views.py</code></p>
  <pre><code>class PersonDetail(generics.RetrieveUpdateDestroyAPIView):
      serializer_class = PersonSerializer
  
      def get_object(self):
          person_id = self.kwargs.get('pk',None)
          return Person.objects.get(pk=person_id) 
  </code></pre>
  <p>How do I add permissions so that only authenticated user can add,update delete or retrieve objects from the person list in the api. And read-only permissions for non authorized users. I tried going through the docs but it is all very confusing. Can someone explain?</p>