tree shaking, webhook, restful api, aria-live: polite

1. 

tree shaking: 簡單說即"移除無用的程式" https://medium.com/starbugs/%E7%B2%BE%E6%BA%96%E7%9A%84%E6%89%93%E5%8C%85-webpack-%E7%9A%84-tree-shaking-ad39e185f284

2.

webhook:

https://pipedream.com/docs/api/rest/webhooks/#send-events-from-an-existing-event-source-to-a-webhook

3.

restful api: https://ithelp.ithome.com.tw/articles/10230223

4.

aria-live: polite

https://lepture.com/zh/2017/fe-live-regions

5.  Can JavaScript Object Keys Have Spaces? and what about hyphen case(also called kebab case or kebab-case)  and underscores (also called snake case or snake_case)?

const a = { "hi everyone":  "hello" };

const b = { "hi-everyone":  "hello" };

const c = { "hi_everyone":  "hello" };

console.log(a["hi everyone"]); // hello

console.log(b["hi-everyone"]); // hello

console.log(c.hi_everyone); // hello