Add authors to attribution scope explainer

Adding authors to attribution scope explainer

attribution_scopes.md

@@ -7,6 +7,7 @@ _Note: This document describes possible new functionality in the Attribution Rep
 
 **Table of Contents**
 
+- [Authors](#authors)
 - [Goals](#goals)
 - [Pre-Attribution Filtering](#pre-attribution-filtering)
   - [API changes](#api-changes)
@@ -18,7 +19,14 @@ _Note: This document describes possible new functionality in the Attribution Rep
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
-<br>
+## Authors
+* Arpana Hosabettu ([email protected])
+* Feifei Ji ([email protected])
+* Vikas Sahu ([email protected])
+
+
+## Introduction
+
 The current attribution logic in the Attribution Reporting API may not be ideal for use-cases where an API caller needs finer-grained control over the attribution granularity (e.g. campaign, product, conversion ID, etc.) before a source is chosen for attribution. Currently available features such as top-level filters are not sufficient for this use-case because they happen after a source has been selected (i.e. after destination matching), which results in either no attribution occurring or incorrect attribution depending on the top-level filters that are set. We can support this use-case by allowing registrations to specify predefined attribution scopes that will be considered for filtering *before* attributing a source, in order to more efficiently extract utility from the API. 
 
 ## Goals