Fix the html output of the QObjectXmlModel example.

Added a title to the XQuery file to prevent generating an invalid
self-closing title tag in the html output.

Task-number: QTBUG-31525

Change-Id: Ieef162ebc9a89028b7cde81d0b42c649232488c7
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>