开展SCRUM的过程中，经常碰到的问题就是团队不知道如何书写一个好的用户故事。所以预备用几章细化了用户故事部分
** ** A user story describes functionality that will be valuable to either a user or purchaser of a system or software. User stories are composed of three aspects:
-a written description of the story used for planning and as a reminder
-conversations about the story that serve to flesh out the details of the story
