Add new definition for JSON files and ReST files.

Resolves: #66284
Releases: master
Change-Id: I1b7052f37180c6d5be7c350b43df3936c33ed501
Reviewed-on: http://review.typo3.org/38493


Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Ingo Renner <ingo@typo3.org>
Tested-by: Ingo Renner <ingo@typo3.org>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>