adding info about DNS configuration on Appuio CLoud

Author: [email protected]

docs/modules/ROOT/pages/vshn-managed/nextcloud/collabora.adoc

@@ -14,9 +14,11 @@ spec:
     service:
       collabora:
         enabled: true
-        fqdn: my-collabora.example.com
+        fqdn: my-collabora.example.com # <1>
 -----
 
+<1> Your full qualified domain name. For our Appuio Cloud offering, You can learn more how to configure your DNS settings https://docs.appuio.cloud/user/how-to/getting-a-certificate.html[here].
+
 This will create a Collabora service with the specified FQDN. The Collabora service will be available at `https://my-collabora.example.com` and autoconfigured in your Nextcloud instance. 
 
 NOTE: To get more information about all available configuration options, please see the xref:references/crds.adoc#k8s-api-github-com-vshn-component-appcat-apis-vshn-v1-vshnnextcloud[API Reference]