[TASK] Switch to typo3/cms-styleguide

Styleguide moved from 7elix/styleguide to typo3/cms-styleguide

Change-Id: Ib11cd3d21121214ed5828aa26166d4a7b1419a3c
Resolves: #80118
Releases: master
Reviewed-on: https://review.typo3.org/51940


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>