Use 'true' rather than '1' for archived flag

api/client-server/v1/sync.yaml

@@ -45,10 +45,10 @@ paths:
           description: |-
             Whether to include rooms that the user has left. If absent then
             only rooms that the user has been invited to or has joined are
-            included. If set to "1" then rooms that the user has left are
+            included. If set to "true" then rooms that the user has left are
             included as well.
           required: false
-          x-example: "1"
+          x-example: "true"
       responses:
         200:
           description: "The events received, which may be none."