Update "About OSC" page

Author: apinnick

_topic_maps/_topic_map.yml

@@ -2892,8 +2892,8 @@ Name: OpenShift sandboxed containers
 Dir: sandboxed_containers
 Distros: openshift-enterprise
 Topics:
-- Name: Documentation moved
-  File: sandboxed-containers-moved
+- Name: About OpenShift sandboxed containers
+  File: about-openshift-sandboxed-containers
 ---
 Name: Observability
 Dir: observability

sandboxed_containers/about-openshift-sandboxed-containers.adoc

@@ -0,0 +1,17 @@
+:_mod-docs-content-type: ASSEMBLY
+include::_attributes/common-attributes.adoc[]
+[id="about-openshift-sandboxed-containers"]
+= About {osc}
+
+:context: about-openshift-sandboxed-containers
+
+toc::[]
+
+{osc} provide security by running containerized applications in lightweight virtual machines. This architecture isolates your workloads from other workloads on the cluster and does not require significant changes to your existing workflows.
+
+Confidential Containers extend {osc} and provide an additional layer of security. They ensure that your workloads are isolated from hypervisors and cloud providers. Confidential Containers protect data in use by leveraging hardware-based Trusted Execution Environments, which are verified by the Trustee attestation service.
+
+[NOTE]
+====
+Because {osc} releases on a different cadence from {product-title}, its documentation is now available as a separate documentation set at link:https://docs.redhat.com/en/documentation/openshift_sandboxed_containers[Red Hat {osc}].
+====