Update appcds.adoc

Mention the appcds.use-container flag

docs/src/main/asciidoc/appcds.adoc

@@ -14,17 +14,19 @@ This reference guide explains how to enable Application Class Data Sharing in yo
 == What is Application Class Data Sharing (AppCDS)?
 
 link:https://docs.oracle.com/en/java/javase/17/docs/specs/man/java.html#application-class-data-sharing[Application Class Data Sharing] is a JVM feature that helps reduce the startup time and memory footprint of a JVM application.
-This is achieved by having the JVM create a pre-processed shared archived of classes that are loaded at startup time. As these classes
+This is achieved by having the JVM create a pre-processed shared archived of classes that are loaded at startup time.
+As these classes
 are loaded every time the application starts, AppCDS is a conceptually simple way of improving the application startup time,
-without the application itself having to be coded or configured in a specific way. How much of an improvement depends on many factors, such as the number of classes loaded, the underlying hardware etc.
+without the application itself having to be coded or configured in a specific way.
+How much of an improvement depends on many factors, such as the number of classes loaded, the underlying hardware etc.
 
 == Vanilla AppCDS generation
 
 The main downside of creating AppCDS manually for an application is that their generation requires launching the application with special flags and obtaining the archive in a step before the application is deployed to production.
 
 NOTE: The exact process depends on the JVM version being used as newer JVM have incrementally made the process easier.
 
-This fact makes the use of AppCDS difficult to use for real world deployments where a CI pipeline is responsible for building and deploying applications.
+This fact makes AppCDS difficult to use for real world deployments where a CI pipeline is responsible for building and deploying applications.
 
 == AppCDS in Quarkus
 
@@ -95,7 +97,11 @@ AppCDS has improved significantly in the latest JDK releases. This means that to
 
 === Usage in containers
 
-When building container images using the `quarkus-container-image-jib` extension, Quarkus automatically takes care of all the steps needed to generate the archive
-and make it usable at runtime in the container.
+When building container images using the `quarkus-container-image-jib` extension, Quarkus automatically takes care of all the steps needed to generate the archive and make it usable at runtime in the container.
 
-This way, by simply setting `quarkus.package.jar.appcds.enabled` to `true` the generated container can benefit from a slight reduction in startup time and memory usage.
+This way, by simply setting `quarkus.package.jar.appcds.enabled` to `true`, containers using the generated image can benefit from a slight reduction in startup time and memory usage.
+
+You may see that Quarkus starts a container to generate the AppCDS archive.
+It does this to ensure that the Java version of the build align with that of the generated container image.
+It is possible to opt out of this by setting `quarkus.package.jar.appcds.use-container` to `false`.
+In that case, it is your responsibility to ensure that the Java version that will run the Quarkus application matches that of the machine building it.