Create a domain verification request

This creates a Freestyle Domain Verification Request. It returns a `verificationCode` for your domain. You need to place this code in a TXT record at `_freestyle_custom_hostname.thedomain.com`, then call the [verify domain](/#tag/domains/PUT/domains/v1/verifications) endpoint with the domain to verify it.

curl -X POST "https://api.freestyle.sh/domains/v1/verifications" \
  -H "Content-Type: application/json" \
  -d '{
    "domain": "example.com"
  }'

{
  "id": "1234-5678-9012-3456",
  "domain": "example.com",
  "accountId": "1234-5678-9012-3456",
  "verificationCode": "freestyle-verification-v1-1234-5678-9012-3456",
  "createdAt": "1234567890"
}