Include description in DocumentTypeItemResponseModel (#16503)

src/Umbraco.Cms.Api.Management/Mapping/Item/ItemTypeMapDefinition.cs

@@ -65,6 +65,7 @@ public class ItemTypeMapDefinition : IMapDefinition
         target.Id = source.Key;
         target.Icon = source.Icon;
         target.IsElement = source.IsElement;
+        target.Description = source.Description;
     }
 
     // Umbraco.Code.MapAll

src/Umbraco.Cms.Api.Management/ViewModels/DocumentType/Item/DocumentTypeItemResponseModel.cs

@@ -7,4 +7,6 @@ public class DocumentTypeItemResponseModel : NamedItemResponseModelBase
     public bool IsElement { get; set; }
 
     public string? Icon { get; set; }
+
+    public string? Description { get; set; }
 }