package.json 中修改外部文件添加时间戳

//windows
"windows": "timestamp=$(date \"+%s\") && sed -i \"s/xxxxxx/xxxxxx-$npm_package_version?_t=$timestamp/g\" src/xxxx.json", 

//mac
"mac": "timestamp=$(date \"+%s\") && sed -i \"\" \"s/xxx/xxx-$npm_package_version?_t=$timestamp/g\" src/xxxx.json"