title: add slugified title to url
body: <p>I have a url like <code>/posts/1</code>, where 1 refers to the id of the article in the db.</p>
  
  <pre><code>@bp.route('/&lt;post_id&gt;')
  @login_required
  def post(post_id):
      """ find the post and then show it """
      p = Post.query.get(post_id)
      return render_template("post/single_post.html", post=p)
  </code></pre>
  
  <p>However, what I would like to do is have a url with some sort of slugified title in it, like <code>/posts/1/my_stack_overflow_question_is_bad</code>. I can make a slugify property in the model:</p>
  
  <pre><code>class Post(db.Model):
      __tablename__ = 'posts'
      id = db.Column(db.Integer, primary_key=True)
      title = db.Column(db.String)
      html = db.Column(db.String)
  
      @property
      def slugified_title():
          return slugify(self.title, separator="_", to_lower=True)
  </code></pre>
  
  <p>but how would I put that in the url?</p>