add changelog

Author: samuelcolvin

Diff for: CHANGELOG.md

@@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#2136](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2136))
 - `opentelemetry-resource-detector-azure` Suppress instrumentation for `urllib` call
   ([#2178](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2178))
+- `opentelemetry-instrumentation-fastapi` Add support for configuring header extraction via runtime constructor parameters
+  ([#2241](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2241))
 
 ## Version 1.22.0/0.43b0 (2023-12-14)