@mention issue author (dotnet#10593)

Author: gewarren

.github/policies/author-action.yml

@@ -28,7 +28,8 @@ configuration:
             label: needs-author-action
         then:
         - addReply:
-            reply: This issue has been marked `needs-author-action` and might be missing some important information.
+            reply: >-
+              @${issueAuthor} - This issue has been marked `needs-author-action` and might be missing some important information.
 
       - description: PR reviews with "changes requested" applies the needs-author-action label
         if: