Make clear that ovh_domain_zone_record.subdomain can be an empty string

[Stoakes]

Description

ovh_domain_zone_record.subdomain attribute is specified as required. Yet, it can be empty.
This PR aims at saving the others a bit of time by making clear that you can create a record with the same name of the zone through Terraform.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (improve existing resource(s) or datasource(s))
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

Manually against OVH API. Here is the snippet:

Terraform used the selected providers to generate the following execution plan. Resource actions are
indicated with the following symbols:
  + create
  ~ update in-place
-/+ destroy and then create replacement

Terraform will perform the following actions:

  # ovh_domain_zone_record.record_noprefix will be created
  + resource "ovh_domain_zone_record" "record_noprefix" {
      + fieldtype = "A"
      + id        = (known after apply)
      + target    = "111.111.111.111"
      + ttl       = 600
      + zone      = "some-domain-name-of-us.ovh"
    }

Plan: 1 to add.


Do you want to perform these actions?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes


ovh_domain_zone_record.record_noprefix: Creating...
ovh_domain_zone_record.record_noprefix: Creation complete after 1s [id=redacted]

Apply complete! Resources: 1 added.

Test Configuration:

• Terraform version: Terraform v1.4.2 on linux_amd64

• Existing HCL configuration you used:

resource "ovh_domain_zone_record" "record_noprefix" {
  zone      = local.dns_zone
  subdomain = ""
  fieldtype = "A"
  ttl       = "600"
  target    = "111.111.111.111"
}

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings or issues
• I have added acceptance tests that prove my fix is effective or that my feature works
• New and existing acceptance tests pass locally with my changes
• I ran succesfully go mod vendor if I added or modify go.mod file

[scraly]

Thanks :)