Update changelog

Author: berndverst

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Protos are compiled with gRPC 1.62.3 / protobuf 3.25.X instead of the latest release. This ensures compatibility with a wider range of grpcio versions for better compatibility with other packages / libraries ([#36](https://github.com/microsoft/durabletask-python/pull/36)) - by [@berndverst](https://github.com/berndverst)
 - Http and grpc protocols and their secure variants are stripped from the host name parameter if provided. Secure mode is enabled if the protocol provided is https or grpcs ([#38](https://github.com/microsoft/durabletask-python/pull/38) - by [@berndverst)(https://github.com/berndverst)
+- Improve ProtoGen by downloading proto file directly instead of using submodule ([#39](https://github.com/microsoft/durabletask-python/pull/39) - by [@berndverst](https://github.com/berndverst)
 
 ### Updates