OSSMDOC-313: Document OSSM ability to copy annotations

Author: jwendell

modules/ossm-auto-route.adoc

@@ -44,6 +44,13 @@ gateway1-scqhv www.bookinfo.com            istio-ingressgateway   <all>
 
 If the gateway is deleted, {ProductName} deletes the routes. However, routes created manually are never modified by {ProductName}.
 
+[id="ossm-auto-route-annotations_{context}"]
+= Annotations
+
+Sometimes specific annotations are needed in an OpenShift Route. For example, some advanced features in OpenShift Routes are managed via xref:../../networking/routes/route-configuration.adoc[special annotations]. For this and other use cases, {ProductName} will copy all annotations present in the Istio Gateway resource (with the exception of those starting with `kubectl.kubernetes.io`) into the managed OpenShift Route resource.
+
+If you need specific annotations in the OpenShift Routes created by {ProductShortName}, create them in the Istio Gateway resource and they will be copied into the OpenShift Route resources managed by the {ProductShortName}.
+
 [id="ossm-auto-route-enable_{context}"]
 = Disabling automatic route creation