D6560: Update/adapt kmag docbooks to kf5

[Yuri Chornoivan]

yurchor accepted this revision as: yurchor.
This revision is now accepted and ready to land.

REPOSITORY
  R428 KMag

REVISION DETAIL
  https://phabricator.kde.org/D6560

To: lueck, #documentation, yurchor
Cc: ltoscano