[DOCS] Fixes broken links to Cloud docs

Author: lcawl

docs/installing-stack.asciidoc

@@ -72,4 +72,4 @@ Elastic Cloud is the official hosted Elasticsearch and Kibana offering from Elas
 
 Some Elastic Cloud features can be used only with a specific  link:https://www.elastic.co/cloud/as-a-service/subscriptions[subscription level]. For example, you can install custom plugins, dictionaries, and scripts only if you are a Gold or Platinum customer.
 
-To learn more about Elastic Cloud, see our {cloudref}/getting-started.html[getting started documentation]. Or link:https://www.elastic.co/cloud/as-a-service/signup[sign up for a free trial] and start exploring hosted Elasticsearch within minutes.
+To learn more about Elastic Cloud, see our {cloudref}/ec-getting-started.html[getting started documentation]. Or link:https://www.elastic.co/cloud/as-a-service/signup[sign up for a free trial] and start exploring hosted Elasticsearch within minutes.

docs/upgrading-stack.asciidoc

@@ -140,5 +140,5 @@ To avoid downtime on production clusters due to major version upgrades:
 
 . Delete the old cluster to stop incurring additional costs. You are billed extra only for the time that the additional cluster was running. Billing for usage is by the hour.
 
-To learn more about the upgrade process on Elastic Cloud, see {cloudref}/upgrading.html[
-Upgrade Versions] and {cloudref}/cluster-config.html[Configuring Elastic Cloud].
+To learn more about the upgrade process on Elastic Cloud, see {cloudref}/ec-upgrading.html[
+Upgrade Versions] and {cloudref}/ec-deployment-config.html[Configuring Elastic Cloud].