Propose Categories already used

[mklemme1]

Is your feature request related to a problem? Please describe.

The current calendar supports categories. The list of categories is hard-coded and cannot be modified (see #1644) . That's not helpful for many use cases. We, for instance, have a calendar of events that many people maintain. We use categories to distinguish different types of events, like internal and external events.

Describe the solution you'd like In the categories selection list, list all the categories that were used in entries of the last two years and the future.

Describe alternatives you've considered Configuring a list (see #1644) would also work. This solution is probably easier to implement (no extra GUI)