add spellCheck, autoCorrect, autoFocus, role <Editor> properties to docs

I currently just need the default browser spell check, but it seems that you’d want to pass a spellCheck property to the root <div> (along with other standard event handlers like onClick).

[MerlinMason]

Ahh right, yeah I’m using the latest version but couldn’t find anything in the docs for these options… Searching through the source code I’ve managed to get the following working.

import { Editable } from "slate-react";

...

<Editable
    autoCapitalize="sentences"
    autoCorrect="true" // "true" should be passed as string
/>

Hopefully that’s useful to someone else 😃

[padunk]

If someone need it:

<Editable
    autoCapitalize="false"
    autoCorrect="false"
    spellCheck="false"
/>

Slate 0.65…3