docs: node-files.md shows a pre-v1.12 node file as the freshly written one #258

The first example on the node-files page shows a format talm no longer writes by default. The "Anatomy" section of docs/configuration/node-files.md calls it a freshly written nodes/node1.yaml, but it carries machine.network.interfaces, nameservers and cluster.clusterName, which is the single-document shape talm renders below Talos v1.12.

The presets pin v1.12 and v1.13 on main, and v1.14 once #253 lands. A node file rendered at those contracts has HostnameConfig, ResolverConfig and LinkConfig documents, and from v1.14 KubeClusterConfig and the other Kubernetes documents instead of the cluster fields. A reader comparing their own file with the page sees two different formats and nothing says which contract the example belongs to.

Either label the example with its contract or replace it with a v1.14 render.