Improve categories

One-sentence description

Improve categories

Why?

Because it's not really useful right now, everything is marked as 'Other'

Current implementation

• Drinks
• Activity
• Lunch Lecture
• General Meeting
• Workshop
• Alumni
• Party
• Other

Suggested implementation

• Alumni (old: Alumni)
• Education (old: Workshop + Lunch Lecture)
• Career (some workshops should go here, manual intervention)
• Leisure (old: Drinks + Party, now also: paintball + lasertag etc)
• Association Affairs (old: GM, now also: SNIC info meeting, board interest meetings) (Verenigingszaken)
• Other (old: Other + Activity)

Important: this requires migrations to changes the categories of existing events to the new ones!