Merge pull request #5304 from segmentio/snap-products

adding description for support of product arrays with Snap CAPI

Author: forstisabella

src/connections/destinations/catalog/actions-snap-conversions/index.md

@@ -70,6 +70,14 @@ If you want to send a Snap Event Type that Segment doesn’t have a prebuilt map
 
 The Snapchat Conversions API only supports sending Event Types that are in the [predefined `event_type` list](https://marketingapi.snapchat.com/docs/conversion.html#conversion-parameters){:target="_blank"}. This includes custom events. You must use `CUSTOM_EVENT_1`, `CUSTOM_EVENT_2`, `CUSTOM_EVENT_3`, `CUSTOM_EVENT_4`, or `CUSTOM_EVENT_5` as the Event Type. Events sent with an invalid event type will fail with an `Unrecognized event type` error. 
 
+### Single or multiple products or items
+It's possible to send details of either single or multiple products/items in a single conversion event. 
+- **Single product/item**: Use the "Item ID", "Item Category" and "Brand" fields. 
+- **Multiple products/items**: Use the "Products" field which accepts an array of products / items. 
+
+### Specifying the total value of a purchase
+The "Price" field should be used when specifying the total value of a purchase, and should contain a numeric value only. e.g. 99.5. 
+
 ### Required parameters and hashing
 To match visitor events with Snapchat ads, Snap requires that one or a combination of the following parameters are sent to the Conversions API:
 - Email