Update MapperClassTemplate.cs

Author: timmac-qmc

src/EntityFrameworkCore.Generator.Core/Templates/MapperClassTemplate.cs

@@ -123,6 +123,7 @@ private void GenerateConstructor()
                         break;
                     case ModelType.Create:
                         CodeBuilder.AppendLine($"CreateMap<{modelFullName}, {entityFullName}>();").AppendLine();
+                        CodeBuilder.AppendLine($"CreateMap<{entityFullName}, {modelFullName}>();").AppendLine();
                         break;
                     case ModelType.Update:
                         updateFullName = modelFullName;