storage/persistent-storage-nfs: Link to RHEL 8 docs

See: openshift#66588

storage/persistent_storage/persistent-storage-nfs.adoc

@@ -16,7 +16,7 @@ distinct cluster resource, making the volume more susceptible to conflicts.
 [role="_additional-resources"]
 .Additional resources
 
-* https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/storage_administration_guide/ch-nfs[Network File System (NFS)]
+* https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/managing_file_systems/mounting-nfs-shares_managing-file-systems[Mounting NFS shares]
 
 include::modules/storage-persistent-storage-nfs-provisioning.adoc[leveloffset=+1]