post:
  summary: 新建一条discussion.
  tags:
    - discussion
  description:
  parameters:
    - name: title
      in: path
      required: false
      description: title of discussion 建立新问题时, title为必填项目
      schema:
        type: string
    - name: content
      in: path
      required: false
      description: content of discussion
      schema:
        type: string
    - name: parent
      in: path
      required: false
      description: 回答的问题的id. 建立问题时无需此参数。建立回答时需要。
      schema:
        type: uuid
  responses:
    "200": # status code
      description: A JSON array of user names
      content:
        application/json:
          schema:
            type: object
            properties:
              ok:
                type: boolean
              message:
                type: string
              data:
                type: object
                $ref: "./data.yaml"