Doc: Added link to Qt Creator's Qt Quick projects page to QML App page.

The link is appropriate in that section.

Task-number: QTBUG-33595
Change-Id: Ib5c2463ded9a741fe987a120d7cec40ec100351d
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>