Merge pull request #1113 from photon-garden/patch-1

Update custom domain docs to mention limitations around additional DNS records.

content/cloud/custom-domain.md

@@ -29,6 +29,8 @@ Currently, you can apply a maximum of one custom domain to your Spin application
 
 Note that this propagation is generally performed in a reasonable time frame (minutes/hours). However, in some cases, propagation can take up to 72 hours. You can check the DNS record types for your domain name using the [Google Public DNS](https://dns.google/) service.
 
+Be aware that updating your domain's nameserver records will cause any additional records you've set through you registrar to no longer take effect. This includes, for example, TXT or MX records for services like Google Workspace. You can work around this by connecting your Fermyon Cloud app to a subdomain. But if you need to use the apex domain (example.com rather than app.example.com) and you also need to set additional DNS records, you should choose a different hosting service for the time being.
+
 ### Next Steps
 
 * Follow the [Ferymon Cloud Custom Domains tutorial](./custom-domains-tutorial.md) to add your custom domain.