应用: 淘宝
任务: 打开淘宝，搜索“手机壳”，购买第一个商品
操作步骤:
step_id: 0
action: CLICK
step_id: 1
action: CLICK
step_id: 2
action: TYPE
type_text: 手机壳
step_id: 3
action: CLICK
step_id: 4
action: CLICK
step_id: 5
action: CLICK
step_id: 6
action: CLICK