Added a note on CNV with OLM disconnected or proxy

Author: e-minguez

virt/install/preparing-cluster-for-virt.adoc

@@ -18,6 +18,10 @@ In {VirtProductName} clusters installed using installer-provisioned infrastructu
 
 * You must manage your Compute nodes according to the number and size of the virtual machines that you want to host in the cluster.
 
+* To deploy {VirtProductName} in a disconnected environment, you must xref:../../operators/admin/olm-restricted-networks.adoc#olm-restricted-networks[configure Operator Lifecycle Manager on restricted networks].
+
+* To use proxy with {VirtProductName}, you must xref:../../operators/admin/olm-configuring-proxy-support.adoc#olm-configuring-proxy-support[configure proxy support in Operator Lifecycle Manager].
+
 {VirtProductName} works with {product-title} by default, but the following installation configurations are recommended:
 
 * Configure xref:../../monitoring/understanding-the-monitoring-stack.adoc#understanding-the-monitoring-stack[monitoring] in the cluster.