iCal export: Implement token management
The hidden section https://foodsharing.de/?page=settings&sub=calendar to generate an authorization token for calendar exports via ical would need some improvement, if we want that public. Mainly listing the existing keys and a button to remove it would be fine as a first step.
Still, that feature is very alpha. Google complicates this additionally as putting this in your google account (what most people will do) synchronizes only once a day which may not be enough.