Update CHANGELOG with async Redis support

Author: sd2k

CHANGELOG.md

@@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - `opentelemetry-instrument` and `opentelemetry-bootstrap` now include a `--version` flag
   ([#1065](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1065))
+- `opentelemetry-instrumentation-redis` now instruments asynchronous Redis clients, if the installed redis-py includes async support (>=4.2.0).
+  ([#1076](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1076))
 
 ## [1.11.1-0.30b1](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.11.1-0.30b1) - 2022-04-21