Update Terraform import resource documentation

Hi Guys,

I found that your documentation how to import resource is out of date.

currently there is:
terraform import cloudflare_record.mitigateddos_net_mitigateddos_net mitigateddos.net/6702ceac85496311b1fa86a4ecc2fd47

but it not works, the right command is not DNS_ZONE/DOMAIN_HASH, but DNS_ZONE_HASH/DOMAIN_HASH instead, for example
terraform import cloudflare_record.mitigateddos_net_mitigateddos_net cc89b8b62737e58d06eb10dd7e0d6798/6702ceac85496311b1fa86a4ecc2fd47

please fix, as spend 30 minutes to realize this
Terraform V 0.12.23
terraform-providers/cloudflare) 2.4.1…