Cherry-pick KMainWindow documentation fixes to KF5
This MR is a cherry-pick from the changes I sent to master
to add to the KF5
branch.
I think I did this right.
git clone git@invent.kde.org:frameworks/kxmlgui.git
cd kxmlgui
git switch kf5
git branch kmainwindow-kf5
git switch kmainwindow-kf5
git cherry-pick 770bca68
git push --set-upstream origin kmainwindow-kf5