¥Exports sugar
新增于: v12.11.0
如果 "." 导出是唯一的导出，则 "exports" 字段为这种情况提供了语法糖，即直接的 "exports" 字段值。
¥If the "." export is the only export, the "exports" field provides sugar
for this case being the direct "exports" field value.
{
"exports": {
".": "./index.js"
}
}
可以写成：
¥can be written:
{
"exports": "./index.js"
}