Add change vs input event description

The Synthetic Events docs for form events points to the Forms doc page as a reference for onChange, onInput, onInvalid, and onSubmit, but the Form page does not go into any detail about these events, and more importantly, how React's change and input events differ from the DOM events of the same name.

It appears a small note used to exist in the Form doc, but has been removed.

A short note about the change event exists in the DOM Elements doc. This was not an obvious place to look to for this information to me, and it does not address the input event. At the very least, this should probably be link to in the Synthetic Events doc, if no other changes are made.

I would like to see a more thorough description of the change and input events and when to use them in the Form doc.

从 issue 中链接的 Synthetic Events form-events 部分、Forms documentation 和 DOM Elements onChange 部分开始。将它们当前的覆盖范围与 issue 中要求区分 React 的 change 事件和 input 事件进行比较，并检查所引用的 pull request，了解之前的措辞。完成的标准是 Forms documentation 解释这两个事件以及何时使用它们，或者明确链接到该解释。