Use notifier for subscribe/unsubscribe to doc

Now that we have the unsubscribe widget, we can use it for the subscribe/unsubscribe on docs.
We should avoid setting a timeout with zero delay, since it would trigger a minimum delay set in the browser

https://developer.mozilla.org/en-US/docs/Web/API/window.setTimeout#Minimum.2F_maximum_delay_and_timeout_nesting