Update index.md (#1002)

added a clarification for the FB standard event

Co-authored-by: LRubin <[email protected]>

Author: irinasayshi

src/connections/destinations/catalog/facebook-pixel/index.md

@@ -120,6 +120,8 @@ Here is how you'd specify standard events in the settings view:
 
 ![event mapping](images/event-mapping.png)
 
+You can map more than one Track event to the same Facebook standard event.
+
 ### Legacy Events
 
 To send *Legacy Conversion* events, use the Segment setting called "Legacy Conversion Pixel IDs". Any events that appear in that mapping will be sent to Facebook with the specified Pixel ID used as the Facebook Pixel `eventName`. Conversion events only support `currency` and `value` as event properties, so only these will be associated with the event. `currency` will default to "USD" if left out.