Missing `node_pools` variable in beta-private-cluster documentation

[fathom-ben]

TL;DR

In the README for beta-private-cluster, the gpu_driver_version arg is missing from the node_pools variable list.

Expected behavior

The docs should cover all node_pools args.

Observed behavior

The docs are missing (at least) this arg.

Terraform Configuration

N/A

Terraform Version

N/A

Additional information

No response