Doc: the Qt Quick UI project wizards were combined

You now select the imports on the second page of the
wizard.

Change-Id: I07a2519ea31edae547865792b0c409872f5ac09f
Reviewed-by: Jarek Kobus <jaroslaw.kobus@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Doc: update screenshot of Qt Quick editors

In the "User Interface" topic.

Change-Id: I853faf304869e6fe13344137c91b0f046edc4a6a
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>