As with other one-time announcements, we'd like to send an email to all Wikipedia Library users letting them know that search is available and that the on-wiki notification will start rolling out soon.
This should be translatable and sent in the user's preferred language.
Subject: The Wikipedia Library: Search feature now available!
Text: https://docs.google.com/document/d/1YdiDTyritNgjpVB-Zd33tYUQ94KK6CNgc-URlsPBYrE/edit
Please merge this to master so that it is translatable, but wait until we've had a few translations on 2021-10-07 before triggering the email.