应用: 今日头条
任务: 启动今日头条，进入商城，找找折扣商品
操作步骤:
step_id: 0
action: CLICK
step_id: 1
action: CLICK
step_id: 2
action: CLICK
step_id: 3
action: TYPE
type_text: 打折商品
step_id: 4
action: CLICK
step_id: 5
action: STOP