Update and rename vevent.md to event.md

docs/extensions/strategy/vevent.md → docs/extensions/strategy/event.md

@@ -1,13 +1,15 @@
-# iCal4j Extensions - Strategy: VEVENT
+# iCal4j Extensions - Strategy: Event
 
 ## Overview
 
+Event strategies extend on the [Event](/extensions/concept/event) concept tailored for specific use-cases.
+
+
  | Strategy    | Participants | Transparency | Recurring | Precision | Classification | Links |
 |-------------|--------------|--------------|-----------|-----------|----------------|--------|
 | Meeting     | 2+           | Opaque       | Optional  | Time      | Private        | Agenda, Location |
 | Appointment | 1            | Opaque       | Optional  | Time      | Confidential   | Location |
 | Anniversary | 1            | Transparent  | Annually  | Date      | Public         | Individual |
-| Observance  | 1            | Transparent  | Required | Time      | Public         | Location |
 | Conference  | 1+            | Transparent  | No | Date      | Public         | Organization, Location |
 | Performance  | 1+            | Opaque  | Optional | Time      | Public         | Agenda, Individual+, Organization, Location |
 | Seminar  | 1+            | Opaque  | Optional | Time      | Public         | Agenda, Individual+, Organization, Location |