D14240: Improve API docs a bit

[Aleix Pol Gonzalez]

apol accepted this revision.

REPOSITORY
  R296 KDeclarative

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D14240

To: gladhorn, #plasma, dhaumann, apol
Cc: dhaumann, kde-frameworks-devel, michaelh, ngraham, bruns