checks now the device width and adjusts the initialView

- footermatter-dates
- sicherheitskarten
- late makerspace
- 2+ images
- fixes

fullcalender lokal statt jsdeliver

- added dark/light-mode set to user's system preference
- updated some team-infos
- calendar working in iframe (so far)

- ics geht, aber Darstellung ist noch nicht fertig

- imap
- bilder
- layout
- uvm