Updated DNS alias mode (markdown)

DNS-alias-mode.md

@@ -1 +1,10 @@
-TODO:
+Set domain CNAME:
+
+```sh
+_acme-challenge.example.com  =>   _acme-challenge.exampleAlias.com
+```
+
+
+```sh
+acme.sh  --issue  --issue  -d  example.com --challenge-alias exampleAlias.com --dns dns_cf
+```