Add transitioned site for UKHSA
Add transitioned site for UKHSA

Requested in Zendesk: https://govuk.zendesk.com/agent/tickets/4755642
Follows guidance: https://docs.publishing.service.gov.uk/manual/transition-a-site.html#2-add-a-site-to-the-transition-app

alphagov/transition-config,alphagov/transition-config