old_contents: from django.contrib import admin
  from .models import Home, About, Usually, PortFolio, ETC, Contact
  
  # Register your models here.
  admin.site.register(Home)
  admin.site.register(About)
  admin.site.register(Usually)
  admin.site.register(PortFolio)
  admin.site.register(ETC)
  admin.site.register(Contact)
  
new_contents: from django.contrib import admin
  
subject: fix model error