[cs-cloudflare-worker] Document an issue if zone has no A or AAAA

[LaurenceJJones]

User was experiencing an issue when enabling the worker on all zones, and then the service was constantly restarting the issue was that a zone had no (A or AAAA to be confirmed) and was causing restart so most likely there an issue in the code, this should be handled.

For now we will update the documentation to showcase this.