Except one, all the example documentation are missing
an image.

Task-number: QTBUG-41996
Change-Id: Ib72dbf239810e66a60841a1ba1395e6fbcb3e8fe
Reviewed-by: Martin Smith <martin.smith@digia.com>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>