CNAME adds a CNAME record to the domain. The name should be the relative label for the domain. Using
*for CNAME records is not recommended, as different providers support them differently.
Target should be a string representing the CNAME target. If it is a single label we will assume it is a relative name on the current domain. If it contains any dots, it should be a fully qualified domain name, ending with a
D("example.com", REG_MY_PROVIDER, DnsProvider("R53"),
CNAME("foo", "google.com."), // foo.example.com -> google.com
CNAME("abc", "@"), // abc.example.com -> example.com
CNAME("def", "test"), // def.example.com -> test.example.com