Refactor deployment guide

Keep preparation work here and move Helm chart installation instruction to Helm README

Change-Id: I2d4ad25d2f187bb9369c60ffa725e661dae1f63f
diff --git a/configuration/network.rst b/configuration/network.rst
index 14efe64..dbe6426 100644
--- a/configuration/network.rst
+++ b/configuration/network.rst
@@ -1,3 +1,5 @@
+.. _onos_network_config:
+
 Network Configuration
 =====================
 SD-Fabric uses several different types of network configurations.