[TASK] Documentation module: Fix width/height of icons

Resolves: #63269
Releases: master
Change-Id: Ibe1409aa0fa886e4f51f737932dd30d5ac4e9801
Reviewed-on: http://review.typo3.org/34489
Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Reviewed-by: Xavier Perseguers <xavier@typo3.org>
Tested-by: Xavier Perseguers <xavier@typo3.org>