Update apps.json: Add wisyCMS

wisyCMS is a content mangement system used for instance for the following websites:
https://www.3we.de
https://www.acandis.com
https://www.buendnis-familie-bruchsal.de
https://chantalsauvant.de
https://www.design317.de
https://www.hash.com
https://www.heisenberg-gymnasium.de
https://www.patchwork3d.de
https://www.stadtwerke-bruchsal.de
https://www.targomed.de
https://www.vbi-bw.de
etc.