message: offboard: add missing doc
diff: @@ -82,6 +82,9 @@ public:
  above). */
  };
  + /**
  + * @brief Type for Position commands in NED (North East Down) coordinates and yaw.
  + */
  struct PositionNEDYaw {
  float north_m; /**< @brief Position North in metres. */
  float east_m; /**< @brief Position East in metres. */
  