doc: Add Example Of Network Data

[irishgordo]

• adding example of network data

Resolves: doc/add-net-data

[cclose]

I'm pretty sure that the docs are generated using tfplugindocs

I think you need to update the corresponding file in examples/resources/harvester_cloudinit_secret/resource.tf

Not a contributor/maintainer myself, but I was also looking into a documentation issue.

[irishgordo]

@cclose - thanks for that mention 😄 👍 - I will be sure to update this draft PR with those changes