Explain how to restore a wholly stubbed object
Explain how to restore a wholly stubbed object

I'm proposing this change based on [this issue](https://github.com/sinonjs/sinon/issues/1553).

Should this explanation be more specific? The only way I was able to access this method was by importing it directly with
```js
import restore from 'sinon/lib/sinon/util/core/restore.js'
```
Is there a more direct way to use it?
cjohansen/Sinon.JS,mroderick/Sinon.JS,fatso83/Sinon.JS,fatso83/Sinon.JS,fatso83/Sinon.JS,mroderick/Sinon.JS,cjohansen/Sinon.JS,mroderick/Sinon.JS,cjohansen/Sinon.JS