Add Integration link in doc index page

Signed-off-by: Yang Xu <yang.xu@futurewei.com>
Issue-ID: DOC-489
Change-Id: I3d198db2d24aac9e55b809709a3b9f5755f49a75
diff --git a/docs/guides/onap-developer/developing/index.rst b/docs/guides/onap-developer/developing/index.rst
index 13b22f9..b88790e 100644
--- a/docs/guides/onap-developer/developing/index.rst
+++ b/docs/guides/onap-developer/developing/index.rst
@@ -159,12 +159,11 @@
 Integration
 -----------
 
-* ONAP Casablanca release content is specified within a list of project
-  artifact versions available in the form of
-  a :ref:`manifest<doc-release-manifest>`.
+.. toctree::
+   :maxdepth: 1
+   :titlesonly:
 
-* To install the whole ONAP (from a complete demo solution perspective)
-  refer to :ref:`Setting Up ONAP <demo-installing-running-onap-requirements>`.
+   ../../../submodules/integration.git/docs/index
 
 Logging Analytics
 -----------------