Create placeholders for documenting release by repository

Change-Id: I0e4af607de9e6aac3424676f344714e0d9e6fde8
diff --git a/howto/release/components/onos_components.rst b/howto/release/components/onos_components.rst
index 896b42a..0bc27bb 100644
--- a/howto/release/components/onos_components.rst
+++ b/howto/release/components/onos_components.rst
@@ -1,3 +1,5 @@
+.. _howto_release_components_onos_components:
+
 VOLTHA Components: ONOS
 =======================