[Azure Front Door] REST API Calls result into error when a "." is included into the customDomainName field.

AFD Rest API calls such as [AFD Custom Domains - Get](https://learn.microsoft.com/en-us/rest/api/azure/), [AFD Custom Domains - Update](https://learn.microsoft.com/en-us/rest/api/frontdoor/azurefrontdoorstandardpremium/afd-custom-domains/update) etc. result into error when a "." is included into the customDomainName field.

"error": {
"code": "BadRequest",
"message": "Property 'AfdDomainEntityKey.AfdDomainName' cannot be set to '[hostname.domain.com](http://hostname.domain.com/)'. "
}

The solution here is to replace the "." with "-" to successfully execute the API Call.

It will be helpful if this information is added to the docs. Thank you!

Reference: https://learn.microsoft.com/en-us/answers/questions/1109140/index.html

Start with the linked AFD Custom Domains - Get and AFD Custom Domains - Update REST API documentation, then review the referenced Microsoft Q&A report. Document that customDomainName values containing a period can fail and that replacing periods with hyphens is the stated workaround; done means the limitation and workaround are visible in the relevant API docs.

Written by the indexing model from the issue text.