Add changelog entry

Author: adamantike

CHANGELOG.md

@@ -7,9 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://github.com/open-telemetry/opentelemetry-python/compare/v1.4.0-0.23b0...HEAD)
 
-## [1.4.0-0.23b0](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.4.0-0.23b0) - 2021-07-19
+### Changed
 
+- `opentelemetry-instrumentation-fastapi` Allow instrumentation of newer FastAPI versions.
+  ([#602](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/602))
 
+## [1.4.0-0.23b0](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.4.0-0.23b0) - 2021-07-19
 
 ### Removed
 - Move `opentelemetry-instrumentation` to the core repo.