🌐 Exports sugar
新增于: v12.11.0
如果是'“。”出口是唯一的出口，"exports"田提供糖
对于此情况，则是直接的"exports"场值。
🌐 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"
}