legend 自定义，name和value希望可以增加横向排列和竖向排列 #3812

• I have searched the issues of this repository and believe that this is not a duplicate.

What problem does this feature solve?

统计看起来更直观。图表展示占比，图例展示数量

What does the proposed API look like?

chart.legend({ items:data.map((item,index)=>{ name:item.name, value:item.value, // 这里增加 layout:vertical | horizontal, ......... }) })

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