docs(cloud): add note about custom domains being available on Enterprise Premium plan

Author: hassankhan

docs/content/Cube-Cloud/Configuration/Custom-Domains.mdx

@@ -7,9 +7,8 @@ menuOrder: 5
 
 <InfoBox>
 
-DNS changes can sometimes take up to 15 minutes to propagate, please wait at
-least 15 minutes and/or try using another DNS provider to verify the `CNAME`
-record correctly before raising a new Support ticket.
+This feature is only available on an Enterprise Premier plan. [Contact us][cube-contact]
+for more details.
 
 </InfoBox>
 
@@ -37,3 +36,9 @@ would look like:
 | Name       | Value                                                 |
 | ---------- | ----------------------------------------------------- |
 | `insights` | `colossal-crowville.gcp-us-central1.cubecloudapp.dev` |
+
+DNS changes can sometimes take up to 15 minutes to propagate, please wait at
+least 15 minutes and/or try using another DNS provider to verify the `CNAME`
+record correctly before raising a new support ticket.
+
+[cube-contact]: https://cube.dev/contact