Announce deprecation of legacy storage architecture for GitLab Pages
We need to announce the deprecation of NFS storage for Pages.
To make GitLab Pages cloud-native compatible, starting in GitLab 14.0, we're changing the underlying storage architecture used by GitLab Pages to the [recently introduced ZIP storage](https://docs.gitlab.com/ee/administration/pages/#zip-storage). Your migration to the new zip archives architecture is designed to be automatic. However, if after the migration, some Pages stop working (you see a 404), it likely means automatic migration failed. To ease this transition to zip, a temporary flag `gitlab_pages['use_legacy_storage'] = true` will be available from GitLab 14.0 to 14.3, but it will be removed in GitLab 14.4. This flag will allow GitLab and GitLab Pages to use the non-zip deployments to serve content. In GitLab 13.11 & GitLab 13.12 you will be able to migrate to the new architecture earlier and test it in your environment prior to 14.0.