[Console] Return $this in phpdocs in chained Question methods

| Q             | A
| ------------- | ---
| Fixed tickets | -
| License       | MIT

So any IDE (or Scrutinizer etc) can understand that it isn't necessarily a Question instance, but when called on ChoiceQuestion or ConfirmationQuestion, it will return that class also.

This probably could be done to a lot of other chained functions, but I wanted to know if you are okay with this, and if it's okay to submit to 2.5, or should it be at master instead?


@WouterJ `static` is correct too :tongue: `$this` is a subset of `static`
The question is, whether or not is relevant to know, if the return value is _really_ the same instance, or just of the same type. The behaviour of the IDEs remains exactly the same, so asking me `$this` is mostly decoration.