title: What is the meaning of detail argument in Django ViewSet?
body: <p>I create a custom action method in Django ViewSet and I see  <a href="https://www.django-rest-framework.org/api-guide/viewsets/#marking-extra-actions-for-routing" rel="noreferrer">detail argument</a>. If I set <code>detail=True</code> I can't call this method from URL but if I set <code>detail=False</code>, I can call this method. May I know what is the meaning of detail argument?</p>
  
  <p>Here is my viewset = ></p>
  
  <pre><code>class TimeSheetViewSet(viewsets.ModelViewSet): 
      queryset = TimeSheet.objects.all()
      serializer_class = TimeSheetSerializer
  
      @action(methods=['get'], detail=True)
      def byhello(self, request):        
          return Response({"From Hello":"Got it"})
  </code></pre>
  
  <p>Here are router and URL patterns =></p>
  
  <pre><code>router.register('timesheets_ts', TimeSheetViewSet, base_name='timesheets')
  
  urlpatterns = [   
      path('api/', include(router.urls))  
  ]
  </code></pre>