Add asset inventory and bulk KRM/Terraform export via the config controller to the docs for hybrid (k8s/tf/gcloud) customer asks (2)

Todo: expand on
https://cloud.google.com/docs/terraform/resource-management/export
```
gcloud beta resource-config bulk-export --resource-format=terraform >> gcp_resources.tf
```
within staging docs in https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/wiki

We may be able to reuse the existing config controller in the kcc gke instance