Docs are missing fields for `Line` in `PurchaseOrder`

In the docs for the [`PurchaseOrder` object](https://developer.intuit.com/app/developer/qbo/docs/api/accounting/all-entities/purchaseorder#the-purchaseorder-object), it shows that `Line` is a list of objects, but it does not document the fields that are available in a `Line` object.

For example, in issue #206 the `Received` field is not documented for the `Line` objects that are in a `PurchaseOrder`:


But the `Received` field (and others) are clearly present in the source code:

```java
public class Line implements Serializable, Equals2, HashCode2
{

private final static long serialVersionUID = 1L;
@XmlElement(name = "Id")
protected String id;
@XmlElement(name = "LineNum")
@XmlSchemaType(name = "positiveInteger")
protected BigInteger lineNum;
@XmlElement(name = "Description")
protected String description;
@XmlElement(name = "Amount")
protected BigDecimal amount;
@XmlElement(name = "Received")
protected BigDecimal received;
@XmlElement(name = "LinkedTxn")
protected List linkedTxn;
@XmlElement(name = "DetailType")
@XmlSchemaType(name = "string")
protected LineDetailTypeEnum detailType;
@XmlElement(name = "PaymentLineDetail")
protected PaymentLineDetail paymentLineDetail;
@XmlElement(name = "DiscountLineDetail")
protected DiscountLineDetail discountLineDetail;
@XmlElement(name = "TaxLineDetail")
protected TaxLineDetail taxLineDetail;
@XmlElement(name = "SalesItemLineDetail")
protected SalesItemLineDetail salesItemLineDetail;
@XmlElement(name = "DescriptionLineDetail")
protected DescriptionLineDetail descriptionLineDetail;
@XmlElement(name = "ItemBasedExpenseLineDetail")
protected ItemBasedExpenseLineDetail itemBasedExpenseLineDetail;
@XmlElement(name = "AccountBasedExpenseLineDetail")
protected AccountBasedExpenseLineDetail accountBasedExpenseLineDetail;
@XmlElement(name = "ReimburseLineDetail")
protected ReimburseLineDetail reimburseLineDetail;
@XmlElement(name = "DepositLineDetail")
protected DepositLineDetail depositLineDetail;
@XmlElement(name = "PurchaseOrderItemLineDetail")
protected PurchaseOrderItemLineDetail purchaseOrderItemLineDetail;
@XmlElement(name = "SalesOrderItemLineDetail")
protected SalesOrderItemLineDetail salesOrderItemLineDetail;
@XmlElement(name = "ItemReceiptLineDetail")
protected ItemReceiptLineDetail itemReceiptLineDetail;
@XmlElement(name = "JournalEntryLineDetail")
protected JournalEntryLineDetail journalEntryLineDetail;
@XmlElement(name = "GroupLineDetail")
protected GroupLineDetail groupLineDetail;
@XmlElement(name = "SubTotalLineDetail")
protected SubTotalLineDetail subTotalLineDetail;
@XmlElement(name = "TDSLineDetail")
protected TDSLineDetail tdsLineDetail;
@XmlElement(name = "ItemAdjustmentLineDetail")
protected ItemAdjustmentLineDetail itemAdjustmentLineDetail;
@XmlElement(name = "CustomField")
protected List customField;
@XmlElement(name = "LineEx")
protected IntuitAnyType lineEx;
@XmlElement(name = "ProjectRef")
protected ReferenceType projectRef;

// ...
}
```

There was no documentation on how to get the `Received` value for the lines in a purchase order.

This might be a broader problem with the documentation generator. It might happen anytime a list of objects is documented, not just for `Line`s in a `PurchaseOrder`.