菜单栏 Plugin -> Plugin Manager -> Show Plugin Manager

Plugin Manager 对话框 -> Available 选项卡 -> 勾选 XML Tools -> Install

Would you like to restart now? 对话框 -> Yes

菜单栏 Plugin -> XML Tools -> Pretty print (XML only - with line breaks) 或 快捷键(Ctrl + Alt + Shift + B)

格式化结果