Resolve "CheckStyle Konfiguration"

feature: add checkstyle config

api/src/main/java/de/fitko/fitconnect/api/services/events/EventLogService.java

@@ -18,7 +18,7 @@ public interface EventLogService {
      * Get the {@link EventLog} by caseId.
      *
      * @param caseId unique case identifier
-     * @return
+     * @return EventLog
      */
     EventLog getEventLog(UUID caseId);