Add TODO question for later

SabreTools.DatFiles/DatFile.cs

@@ -445,6 +445,7 @@ namespace SabreTools.DatFiles
         /// Return list of required fields missing from a DatItem
         /// </summary>
         /// <returns>List of missing required fields, null or empty if none were found</returns>
+        /// TODO: Can this be made into a thin wrapper around a RequiredFields Dictionary property?
         protected virtual List<string>? GetMissingRequiredFields(DatItem datItem) => null;
 
         /// <summary>