Renamed and moved a few things

address assignment -> dhcp relay
community -> resource

Change-Id: I807a896d8a8f610eb8af0063ba36ba0f0d55c070
diff --git a/configuration.rst b/configuration.rst
index b960105..9b1fc35 100644
--- a/configuration.rst
+++ b/configuration.rst
@@ -11,7 +11,7 @@
 
     configuration/device-config
     configuration/bridging-unicast
-    configuration/address-assignment
+    configuration/dhcp-relay
     configuration/dual-homing
     configuration/external-connectivity
     configuration/route-service