怎么把下面的数组转为
[{index:1，value：沪上家宴}，{index:2，value：沪上家宴}，{index:3，value：上海市普陀区宜川路}]
index是排序的序号 从1开始 value是对应key的值
[
{
"品牌": "沪上家宴",
"店名": "沪上家宴",
"店址": "上海市普陀区宜川路",
"租金": 900,
"付款周期（月）": 3,
"付款时间": null,
"签约人": "姜春明",
"签约人电话": 13000000000,
"店长": "陆店",
"店长电话": 120000000,
"机器型号": "MKW-1004SH",
"设备序列号": "02F121351519",
"发票抬头": "上海膳德餐饮有限公司",
"合同签约日期": "2018-05-22",
"合同截止日期": "2021-09-01",
"安装调试时间": "2018-06-01",
"备注": "2022.3-5月因疫情未用"
},
{
"品牌": "江宴饭店",
"店名": "江宴饭店",
"店址": "上海市闵行区芦恒路",
"租金": 900,
"付款周期（月）": 3,
"付款时间": null,
"签约人": "徐晓冬",
"签约人电话": 18000000000,
"店长": "无联系人",
"店长电话": null,
"机器型号": "MKW-1004SH",
"设备序列号": "02F121628311",
"发票抬头": "上海伯冉餐饮管理有限公司",
"合同签约日期": "2022-03-01",
"合同截止日期": "2023-02-28",
"安装调试时间": "2019-05-30",
"备注": null
}]
let newArr=arr.map((item,index)=>{
return {index,value:item["品牌"]}
})