refactor: add exercise category

src/things/academic-event.ts

@@ -92,6 +92,7 @@ export type SCAcademicEventCategories =
   | 'course'
   | 'practicum introduction'
   | 'excursion'
+  | 'exercise'
   | 'special';
 
 /**
@@ -152,6 +153,7 @@ export class SCAcademicEventMeta
         'colloquium': 'Kolloquium',
         'course': 'Kurs',
         'excursion': 'Exkursion',
+        'exercise': 'Übung',
         'integrated course': '',
         'introductory class': 'Einführungsveranstaltung',
         'lecture': 'Vorlesung',