Update cloud-tiers.md

:::note Single replica services across all three tiers are meant to be fixed in size(8 GiB, 12 GiB).:::

Author: krithika-ch

docs/en/cloud/manage/cloud-tiers.md

@@ -187,6 +187,8 @@ Caters to large-scale, mission critical deployments that have stringent security
 - Offers [HIPAA](../security/compliance-overview.md/#hipaa) Compliance.
 - Exports Backups to the user's account.
 
+:::note Single replica services across all three tiers are meant to be fixed in size(8 GiB, 12 GiB).:::
+
 ## Upgrading to a different tier
 
 You can always upgrade from Basic to Scale or from Scale to Enterprise.