update release notes

docs/release-notes/v0.33.0.md

@@ -10,6 +10,17 @@ If you're new to Radius, check out our website, [radapp.io](https://radapp.io),
 
 ## Highlights
 
+### Access Kubernetes secrets using PodSpec
+A new guide is now available with instructions on how to patch existing Kubernetes secrets using [PodSpec](https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#PodSpec) definitions and provide them to the environment of a container. Visit the [How-To Guide](https://docs.radapp.io/guides/author-apps/kubernetes/secrets-podspec/) in the Radius documentation to learn more.
+
+### Codecov now enabled in the Radius repo
+
+[Codecov](https://about.codecov.io/) has been added to the [Radius repo](https://github.com/radius-project/radius) and will compare test coverage reports and display results in all pull requests going forward.
+
+## Community Contributions
+
+- Thanks to @gpltaylor for contributing to user experience improvements with `rad group switch` CLI command and fixing the bug with root CA file path for Windows while installing Radius.
+- Thanks to @superbeeny for contributing to the how-to-guide on patching existing Kubernetes secrets using PodSpec.
 
 ## Breaking changes