Document ${pvc.name}, ${pvc.namespace}, ${pv.name} and ${pvc.annotations['...']}

[sathieu]

Is your feature request related to a problem?/Why is this needed

I found those replacements by chance. Documenting them would help others.

Describe the solution you'd like in detail

Documentation of those available expansions, and where they can be used.

Describe alternatives you've considered

Currently, it's only somewhat documented in changelog:

external-provisioner/CHANGELOG/CHANGELOG-1.6.md

Lines 52 to 54 in 6471a8e

	- Default StorageClass secrets are added:
	- csi.storage.k8s.io/secret-name: ${pvc.name}
	- csi.storage.k8s.io/secret-namespace: ${pvc.namespace}

external-provisioner/CHANGELOG/CHANGELOG-5.0.md

Line 18 in 6471a8e

- Added support for PVC annotations in `csi.storage.k8s.io/provisioner-secret-name` StorageClass parameters. For example: `csi.storage.k8s.io/provisioner-secret-name: ${pvc.annotations['xyz']}`. ([#1196](https://github.com/kubernetes-csi/external-provisioner/pull/1196), [@hoyho](https://github.com/hoyho))

Additional context

[sathieu]

I found the doc in: https://github.com/kubernetes-csi/docs/blob/1360f37ede2a97b6d194502131607cb42f2ef291/book/src/secrets-and-credentials-storage-class.md#createdelete-volume-secret

ie: https://kubernetes-csi.github.io/docs/secrets-and-credentials-storage-class.html#createdelete-volume-secret

closing