Describe the bug

https://github.com/hashicorp/vault/blob/main/website/content/docs/auth/kubernetes.mdx describes how to obtain a Kubernetes service account token manually as:

kubectl get secret "$(kubectl get serviceaccount default -o jsonpath='{.secrets[0].name}')"

This is scraping an auto-generated token, rather than requesting one for external use. The auto-generated tokens are only intended for mounting into pods, and with the transition away from secret-based tokens in Kubernetes 1.22+, new secret-based tokens will no longer be auto-generated in future Kubernetes releases (planned starting in Kubernetes 1.24).

While use of secret-based tokens is discouraged due to their weaker security properties, if one is still needed, https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/#manually-create-a-service-account-api-token has instructions for manually creating a secret to contain a long-lived token.

https://github.com/hashicorp/vault/blob/main/website/content/docs/auth/kubernetes.mdx should update to align with or reference those instructions.