Add sample receipt object

docs/Receipt.md

@@ -1,5 +1,111 @@
 # Receipt Objects
 
+## Sample receipt object
+
+This is an example of the data `global.apis.pos.onReceiptChange`
+and `global.apis.pos.onTransactionFinished` send to plugins.
+All data for a PostalPoint transaction is available in its receipt object.
+
+The money-related properties near the bottom of this sample are generated by PostalPoint
+from the items and payments.
+
+### Notes:
+
+* The `due` property will be a negative number if change is owed to the customer.
+* `pendingEmailTo` is set to a suggested email address for the email receipt, and if the receipt
+should actually be emailed, it will be set in `emailTo`.
+* `uuid` is a unique 16-character alphanumeric receipt ID number, which is shown and used in several places.
+The `uuid` is generated using `global.apis.util.uuid.short()`.
+* `customerAccountId` is the UUID for the customer's account, or null if there isn't a customer attached.
+* This example happens to be the object used when test printing a receipt from the PostalPoint
+settings menu, so press that button to see what this is rendered into.
+
+
+```javascript
+{
+    "items": [
+        ReceiptItem.fromJSON({
+            "id": "9100123456789012345678",
+            "label": "Test Package",
+            "text": "Package Details\nTracking # 9100 1234 5678 9012 3456 78\nTo:\nTEST PERSON\nORGANIZATION INC\n123 TEST ROAD\nTESTTOWN TE 99999-0001",
+            "priceEach": 8,
+            "qty": 1,
+            "cost": 0,
+            "retail": 8,
+            "taxRate": 0,
+            "free": false,
+            "barcode": "9100123456789012345678",
+            "certifiedInfo": false,
+            "isMerch": false,
+            "surcharge": false,
+            "toAddress": {
+                "name": "TEST PERSON",
+                "company": "ORGANIZATION INC",
+                "street1": "123 TEST ROAD",
+                "street2": null,
+                "city": "TESTTOWN",
+                "state": "TE",
+                "zip": "99999-0001",
+                "email": null,
+                "phone": null,
+                "country": "US"
+            },
+            "fromAddress": {
+                "name": "TEST PERSON",
+                "company": "ORGANIZATION INC",
+                "street1": "123 TEST ROAD",
+                "street2": null,
+                "city": "TESTTOWN",
+                "state": "TE",
+                "zip": "99999-0001",
+                "email": null,
+                "phone": null,
+                "country": "US"
+            }
+        }),
+        ReceiptItem.fromJSON({
+            "id": "testitem",
+            "label": "Test Item",
+            "text": "",
+            "priceEach": 2,
+            "qty": 1,
+            "cost": 0,
+            "retail": 2,
+            "taxRate": 0.1,
+            "free": false,
+            "barcode": "",
+            "certifiedInfo": false,
+            "isMerch": true,
+            "surcharge": false
+        })
+    ],
+    "payments": [
+        ReceiptPayment.fromJSON({
+            "amount": 10,
+            "type": "cash",
+            "text": "",
+            "id": "testcash"
+        })
+    ],
+    "subtotal": 10,
+    "subtotalFormatted": "$10.00",
+    "tax": 0.2,
+    "taxFormatted": "$0.20",
+    "grandTotal": 10.2,
+    "grandTotalFormatted": "$10.20",
+    "paid": 10.2,
+    "paidFormatted": "$10.20",
+    "due": 0,
+    "dueFormatted": "$0.00",
+    "emailTo": null,
+    "pendingEmailTo": null,
+    "uuid": "1234567890abcdef",
+    "customerAccountId": null,
+    "topTextHTML": "",
+    "bottomTextHTML": ""
+}
+```
+
 ## global.apis.pos.ReceiptItem
 
 ```javascript