docs: tweak wording

Signed-off-by: Kai Dubauskas <kai.dubauskas@doordash.com>

plugins/notifications-backend-module-slack/src/lib/constants.ts

@@ -30,6 +30,6 @@ export const ANNOTATION_SLACK_BOT_NOTIFY = 'slack.com/bot-notify';
 
 /**
  * @public
- * Metadata key containing user entities before resolution
+ * Metadata key containing a list of all user entities before resolution
  */
 export const USER_REFS_FROM_REQUEST_KEY = 'userRefsFromRequest';