ONOS-5411: Introduce basic region config.

Change-Id: I3f58e5758d0b350a9e8a03093a1475dbbacfc446
diff --git a/tools/test/topos/regions-topo-2 b/tools/test/topos/regions-topo-2
index 4180c37..e9616f2 100755
--- a/tools/test/topos/regions-topo-2
+++ b/tools/test/topos/regions-topo-2
@@ -3,10 +3,15 @@
 
 host=${1:-127.0.0.1}
 
+### start up null provider
+
 onos ${host} null-simulation stop custom
 onos ${host} wipe-out please
 onos ${host} null-simulation start custom
 
+
+### Add devices and links
+#
 # null-create-device <type> <name> <#ports> <latitude> <longitude>
 # null-create-link <type> <src> <dst>
 
@@ -37,6 +42,12 @@
 
 EOF
 
+
+### Add regions and associate devices with them
+#
+# region-add <region-id> <region-name> <region-type> <region-master>
+# region-add-devices <region-id> <device-id>...
+
 onos ${host} <<-EOF
 
 region-add r1 Region1 METRO ${host}
@@ -58,6 +69,14 @@
     null:0000000000000009
 
 regions
+EOF
+
+
+### Add layouts, associating backing regions, and optional parent.
+#
+# layout-add <layout-id> <region-id(opt)> <parent-layout-id(opt)>
+
+onos ${host} <<-EOF
 
 layout-add l1 r1
 layout-add l2 r2
@@ -67,6 +86,8 @@
 EOF
 
 
+### Set up debug log messages for classes we care about
+
 onos ${host} <<-EOF
 
 log:set DEBUG org.onosproject.ui.impl.topo.Topo2ViewMessageHandler