Update EKS Guide to use ConfigGroup v2

[EronWright]

This section of the EKS Guide says "This functionality is currently not available in YAML." for the YAML language. Based on the info in this blog post, we can now include a YAML example in this section.

The subsequent section featuring a transformation is still not possible.

Here's a draft of the new content:

resources:
  eks-provider:
    type: pulumi:providers:kubernetes
    properties:
      kubeconfig: ${cluster.kubeconfigJson}
  cluster:
    type: eks:Cluster
  guestbook:
    type: kubernetes:yaml/v2:ConfigGroup
    properties:
      files:
      - "yaml/*.yaml"
    options:
      provider: ${eks-provider}
outputs:
  kubeconfig: ${cluster.kubeconfig}