Update internal links in Kubernetes orchestrator documentation

- Changed links for the remote artifact store and remote container registry sections to point to the correct README files, ensuring accurate navigation within the documentation.

This update aims to enhance the clarity and usability of the Kubernetes orchestrator guide.

Author: strickvl

docs/book/component-guide/orchestrators/kubernetes.md

@@ -40,8 +40,8 @@ To use the Kubernetes orchestrator, we need:
     zenml integration install kubernetes
     ```
 * [Docker](https://www.docker.com) installed and running.
-* A [remote artifact store](../artifact-stores/artifact-stores.md) as part of your stack.
-* A [remote container registry](../container-registries/container-registries.md) as part of your stack.
+* A [remote artifact store](../artifact-stores/README.md) as part of your stack.
+* A [remote container registry](../container-registries/README.md) as part of your stack.
 * A Kubernetes cluster [deployed](kubernetes.md#how-to-deploy-it)
 * [kubectl](https://kubernetes.io/docs/tasks/tools/#kubectl) installed and the name of the Kubernetes configuration context which points to the target cluster (i.e. run`kubectl config get-contexts` to see a list of available contexts) . This is optional (see below).