orientation in simple tr serializer

arkindex/documents/serializers/ml.py

@@ -328,6 +328,7 @@ class SimpleTranscriptionSerializer(serializers.Serializer):
         max_value=1,
         required=False,
     )
+    orientation = EnumField(TextOrientation, default=TextOrientation.HorizontalLeftToRight, required=False)
 
     def validate(self, data):
         if not ('score' in data) ^ ('confidence' in data):