Doc: Adding information about how to run the example.
Doc: Adding information about how to run the example.

-includes a file from qtbase/doc/global/includes
-added to example pages (\example)

Task-number: QTBUG-33597
Change-Id: I1356e12826a7702b4431f815d6ec42b28e21003c
Reviewed-by: J-P Nurmi <b84a892f57a298bb5dae653b4e188948a84d5549@digia.com>

mizukusak/qtquickcontrols,mizukusak/qtquickcontrols,mizukusak/qtquickcontrols