It does not make any sense to document these properties
with the same text, as qdoc will duplicate the text under the
documentation of each and every property in the same documentation
comment, resulting in weird documentation
(such as the element you assign to "left" is the one you move
to when you press the *right* key).

Change-Id: Ic27502a5965cc2b8c61cfdaf887434d3c79256af
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>