qthelp documentation missing examples, inheritance relationships

Looking at the Qt help framework documentation in 5.x releases I've noticed following small issues:

1) The first example box is empty:

After specifying all relevant information in this file, it needs to be compiled by calling: <nothing>

(e.g. http://doc-snapshot.qt-project.org/qt5-stable/qthelp-framework.html)

That means that the reader actually does not learn what command to use to compile Qt help files.

2) The QHelpEngine widgets (which are returned by QHelpEngine methods) seem to inherit QWidget. But the documentations says that QHelpContentWidget and QHelpIndexWidget don't inherit from anything.

E.g.: http://doc-snapshot.qt-project.org/qt5-stable/qhelpindexwidget.html, http://doc-snapshot.qt-project.org/qt5-stable/qhelpcontentwidget.html

3) The qt help index page lists

CONFIG += help

but qmake reports this construct as deprecated - it suggests instead:

QT += help

The class documentation pages also use QT += help.

(e.g. http://doc-snapshot.qt-project.org/qt5-stable/qthelp-index.html)