可选链,空值合并,逻辑空等简化写法babel插件

空值合并运算符（??）Nullish coalescing operator

@babel/plugin-proposal-nullish-coalescing-operator

可选链运算符（?.） Optional chaining operator

@babel/plugin-proposal-optional-chaining

逻辑空赋值（??=）Nullish coalescing assignment

@babel/plugin-proposal-logical-assignment-operators