[#14] Documents: Add DeliveryAncmtList

Elwig/Documents/Document.cs

@@ -90,6 +90,8 @@ namespace Elwig.Documents {
                 name = "WineQualityStatistics";
             } else if (this is PaymentVariantSummary) {
                 name = "PaymentVariantSummary";
+            } else if (this is DeliveryAncmtList) {
+                name = "DeliveryAncmtList";
             } else {
                 throw new InvalidOperationException("Invalid document object");
             }