完成评论功能

1. 定义评论的视图函数
   @app.route('/comment/',methods=['POST'])
   def comment()：
   读取前端页面数据，保存到数据库中
2. 用<input type="hidden" 方法获取前端的"question_id" 
3. 显示评论次数
4. 要求评论前登录
5. 尝试实现详情页面下的评论列表显示

6. <ul class="sss" style="padding-left: 0px;">
               {% for fo in comment %}
                   <li class="list-group-item">
                       <a>{{ fo.author.username }}</a>
                       <span class="badge pull-right">{{ fo.create_time }}</span>
                       <p>{{ fo.detail }}</p>
                       <br>
                   </li>
               {% endfor %}
           </ul>
   

   @app.route('/详情页/<fankui_id>',methods=['GET','POST'])
   def 详情页(fankui_id):
       quest=Fankui.query.filter(Fankui.id == fankui_id).first()
       comment = Comment.query.filter(Comment.fankui_id == fankui_id).all()
   
   
       return  render_template('详情页.html',ques = quest,comment=comment)

   @app.route('/comment/',methods=['POST'])
   @loginFirst
   def comment():
       coment = request.form.get('new_comment')
       autho_id = User.query.filter(User.username == session.get('user')).first().id
       fanku_id = request.form.get('fankui_id')
       comm = Comment(detail=coment, fankui_id=fanku_id,author_id=autho_id)
       db.session.add(comm)
       db.session.commit()
       return redirect(url_for('详情页',fankui_id=fanku_id))