Add missing changelog entry

Signed-off-by: DylanGuedes <djmgguedes@gmail.com>

CHANGELOG.md

@@ -11,6 +11,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 ## Unreleased
 - [#38](https://github.com/thanos-io/objstore/pull/38) GCS: Upgrade cloud.google.com/go/storage version to `v1.43.0`.
 - [#145](https://github.com/thanos-io/objstore/pull/145) Include content length in the response of Get and GetRange.
+- [#157](https://github.com/thanos-io/objstore/pull/157) Azure: Add `tenant_id` and `client_secret` configs.
 
 ### Fixed
 - [#153](https://github.com/thanos-io/objstore/pull/153) Metrics: Fix `objstore_bucket_operation_duration_seconds_*` for `get` and `get_range` operations.