to_4.0.md: opportunity to review Ibexa Cloud changes.

Author: adriendupuis

docs/update_and_migration/from_3.3/to_4.0.md

@@ -219,3 +219,16 @@ Finally, generate the new GraphQl schema:
 ``` bash
 php bin/console ibexa:graphql:generate-schema
 ```
+
+### Ibexa Cloud
+
+Update Platform.sh configuration and scripts.
+
+Generate new configuration with the following command:
+
+```bash
+composer ibexa:setup --platformsh
+```
+
+Review the changes applied to `.platform.app.yaml`, `.platform/` and `bin/platformsh_prestart_cacheclear.sh`,
+merge with your custom settings if needed, and commit them to Git.

docs/update_and_migration/from_3.3/update_from_3.3.md

@@ -317,7 +317,7 @@ Run the following scripts:
 
 #### Ibexa Cloud
 
-Update Platform.sh configuration for PHP and Varnish.
+Update Platform.sh configuration and scripts.
 
 Generate new configuration with the following command: