new_contents: from django.contrib import admin
  
  from lists.models import List
  
  
  class PackageInline(admin.TabularInline):
      model = List.packages.through
      raw_id_fields = ["package"]
      extra = 0
  
  
  class ListAdmin(admin.ModelAdmin):
      list_display = ["name", "user", "created", "modified"]
      list_filter = ["created", "modified"]
      search_fields = ["name", "user__username", "packages__name"]
      raw_id_fields = ["user"]
      exclude = ["packages"]
  
      inlines = [
          PackageInline,
      ]
  
  admin.site.register(List, ListAdmin)
  
subject: add Lists to the admin