new_contents: from django.db import models
  from api.models import Hackathon
  from django.contrib import admin
  from hackfsu_com.admin import hackfsu_admin
  
  
  class PreviewEmail(models.Model):
      hackathon = models.ForeignKey(to=Hackathon, on_delete=models.CASCADE)
      email = models.CharField(max_length=100)
      interest = models.CharField(max_length=100)
      submit_time = models.DateTimeField(auto_now_add=True)
  
      def __str__(self):
          return '[PreviewEmail {} - {}]'.format(self.email, self.interest)
  
  
  @admin.register(PreviewEmail, site=hackfsu_admin)
  class PreviewEmailAdmin(admin.ModelAdmin):
      list_filter = ('hackathon',)
      list_display = ('id', 'email', 'interest', 'submit_time')
      list_editable = ('email', 'interest')
      list_display_links = ('id',)
      search_fields = ('email', 'interest')
      ordering = ('-submit_time',)
  
subject: Add model for preview emails