old_contents: from django import template
  import markdown as md
  import bleach
  
  register = template.Library()
  
  def markdown(value):
      """convert to markdown"""
      return md.markdown(bleach.clean(value))
      
  register.filter('markdown', markdown)
new_contents: from django import template
  import markdown as md
  import bleach
  import copy
  
  register = template.Library()
  
  def markdown(value):
      """convert to markdown"""
      allowed_tags = bleach.ALLOWED_TAGS + ['p', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6']
      return bleach.clean(md.markdown(value), tags = allowed_tags)
      
  register.filter('markdown', markdown)
subject: Fix blockquote missing from markdown filter