slight changes to package structure + naming

src/main/java/mops/gruppen2/domain/event/UpdateGroupTitleEvent.java

@@ -0,0 +1,13 @@
+package mops.gruppen2.domain.event;
+
+import lombok.Getter;
+
+@Getter
+public class UpdateGroupTitleEvent extends Event {
+    String titel;
+
+    public UpdateGroupTitleEvent(long id, long gruppe_id, String user_id, String titel) {
+        super(id, gruppe_id, user_id);
+        this.titel = titel;
+    }
+}