Docs reshuffle

[jacobbednarz]

Updates the registry documentation to match the newer standard and integrate with terraform-plugin-docs.

• Moves website/docs => templates (hand crafted documentation)
• Allows us to delete the hard crafted resource documentation one at a time as we cut them over.
• Contributing docs are now a top level directory.

[github-actions]

Oops! It looks like no changelog entry is attached to this PR. Please include a release note as described in https://github.com/cloudflare/terraform-provider-cloudflare/blob/master/docs/contributing/changelog-process.md.

Example:

```release-note:TYPE
Release note
```

If you do not require a release note to be included, please add the workflow/skip-changelog-entry label.

[github-actions]

This functionality has been released in v3.17.0 of the Terraform Cloudflare Provider.

Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!