Link to the "Announce a deployment" how-to in the Takeoff project
This addresses https://gitlab.com/gitlab-com/infrastructure/issues/1361 and depends on https://gitlab.com/gitlab-org/takeoff/merge_requests/7.
Edited by Rémy Coutable
This addresses https://gitlab.com/gitlab-com/infrastructure/issues/1361 and depends on https://gitlab.com/gitlab-org/takeoff/merge_requests/7.