Merge branch 'brodock/gitlab-backup-cli-readme' into 'master'

Improve gitlab-backup-cli README

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/165041



Merged-by: Smriti Garg <sgarg@gitlab.com>
Approved-by: Sampath Ranasinghe <sranasinghe@gitlab.com>
Approved-by: Achilleas Pipinellis - OOO until November 25th (parental leave) <axil@gitlab.com>
Approved-by: Phillip Wells <pwells@gitlab.com>
Approved-by: Smriti Garg <sgarg@gitlab.com>
Reviewed-by: Achilleas Pipinellis - OOO until November 25th (parental leave) <axil@gitlab.com>
Co-authored-by: Gabriel Mazetto <gabriel@gitlab.com>

gems/gitlab-backup-cli/README.md

-# Gitlab::Backup::Cli
-This gem will contain the Backup CLI logic.
+# GitLab Backup CLI
+## Overview
+
+The GitLab Backup CLI is the new Backup tool for all GitLab installations.
+
+The previous implementation relied on a couple of different approaches to implement backup.
+
+Some relied on rake tasks shipped along with the main codebase. Extra functionality was implemented as part of Omnibus GitLab, and a different implementation was done for Kubernetes.
+
+In this new implementation, we have a Unified approach:
+
+- All the Backup logic is implemented in a single tool.
+- The same tool works across the different installation types.
+- It provides a similar UX no matter which installation type it is running from.
+
+It aims to eventually supersede the previous backup mechanisms:
+
+- [gitlab-backup](https://docs.gitlab.com/ee/administration/backup_restore/backup_gitlab.html#command-line-interface)
+- [backup-utility](https://docs.gitlab.com/charts/backup-restore/backup.html)
+- [alternative strategies](https://docs.gitlab.com/ee/administration/backup_restore/backup_gitlab.html#alternative-backup-strategies)
+
+In addition, the new tool will add a new way of performing Backups when used with supported Cloud providers:
+
+- It will rely on Cloud providers' APIs to perform Backups at scale.
+- It will provide a Unified UX across different Cloud providers' backup capability.
+
+Please check the Blueprint for additional information:
+https://handbook.gitlab.com/handbook/engineering/architecture/design-documents/backup_and_restore/
 ## License