Minor Clarity on Destinations (#840)

Add bit of clarity on destinations being to be both buyer and seller rather than one or other.

Fenced_Frames_Ads_Reporting.md

@@ -47,7 +47,7 @@ The following new APIs will be added for achieving this.
 
 ## reportEvent
 
-Fenced frames can invoke the `reportEvent` API to tell the browser to send a beacon with event data to a URL registered by the worklet in `registerAdBeacon` (see below). Depending on the declared `destination`, the beacon is sent to either the buyer's or the seller's registered URL. Examples of such events are mouse hovers, clicks (which may or may not lead to navigation e.g. video player control element clicks), etc.
+Fenced frames can invoke the `reportEvent` API to tell the browser to send a beacon with event data to a URL registered by the worklet in `registerAdBeacon` (see below). Depending on the declared `destination`(s), the beacon is sent to either the buyer's and/or the seller's registered URL. Examples of such events are mouse hovers, clicks (which may or may not lead to navigation e.g. video player control element clicks), etc.
 
 This API is available from same-origin frames within the initial rendered ad document and across subsequent same-origin navigations, but it's no longer available after cross-origin navigations or in cross-origin subframes. (For this API, for chains of redirects, the requestor is considered same-origin with the target only if it is same-origin with all redirect URLs in the chain.) This way, the ad may redirect itself without losing access to reporting, but other sites can't send spurious reports.