QQmlListProperty should link to examples

http://doc.qt.io/qt-5/qqmllistproperty.html has no examples of how to implement the functions.

It could link to this documentation in its "See also" section, for example:

http://doc.qt.io/qt-5/gettingstartedqml.html#extending-qml-using-qt-c

Although even this documentation doesn't actually show any implementations, it at least tells the user where the full source code can be found (at the end of the article).

Or this:

http://doc.qt.io/qt-5/qtqml-cppintegration-exposecppattributes.html#properties-with-object-list-types