[BUGFIX] RTE: Documentation of enableWordClean is wrong

The HTMLparser properties must be defined under subproperty HTMLparser
of enableWordClean and not directly under property enableWordClean.

Releases: master, 6.2
Resolves: #58105
Change-Id: I0b21e5789aa4db867e0057e484d17f40a26b5c56
Reviewed-on: http://review.typo3.org/33565
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>