[REST API Program model] models.py -> admin.py -> serializer.py(data<->json) -> views.py -> urls.py models.py class Board(models.Model): title = models.CharField(max_length=500) description = models.TextField(blank=True, null=True) content = RichTextUploadingField(blank=True, null=True) view_count = models.IntegerField(default=0, blank=True) display_order = models.IntegerField(default=0, blank=True, null=True) open = models.IntegerField(choices=codes.YESNO, default=0) popup = models.IntegerField(choices=codes.YESNO, default=0) status = models.IntegerField(choices=codes.STATUS, default=1) creator = models.ForeignKey(User, on_delete=models.PROTECT, related_name='board_creator', null=True, blank=True) modifier = models.ForeignKey(User, on_delete=models.PROTECT, related_name='board_modifier',