Document migration from bundled MinIO, Redis, and PostgreSQL
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## Summary
GitLab chart bundles Redis, MinIO, and PostgreSQL charts. These charts are not recommended for production usage.
To ease customers migrating to production-ready solutions, we need to provide documentation to migrate to other solutions.
## Acceptance Criteria
- [x] Object Storage migration tested+documented
- [x] PostgreSQL migration tested+documented
- [x] Redis migration tested+documented
issue