[doxygen] Fix broken groupings

src/blackcore/fsd/flightplan.h

@@ -37,7 +37,8 @@ namespace BlackCore
             //! PDU identifier
             static QString pdu() { return "$FP"; }
 
-            //! Properties @{
+            //! Properties
+            //! @{
             FlightType m_flightType {};
             QString m_aircraftIcaoType;
             int m_trueCruisingSpeed = 0;
@@ -53,7 +54,7 @@ namespace BlackCore
             QString m_altAirport;
             QString m_remarks;
             QString m_route;
-            //! @
+            //! @}
 
         protected:
             FlightPlan();