Added specification

Also did a minor adjustment on intro and architecture

Change-Id: I047ec1c1ee4ef5b421e98ecd242c96d55692fdb9
diff --git a/index.rst b/index.rst
index c154729..becaf30 100644
--- a/index.rst
+++ b/index.rst
@@ -28,6 +28,10 @@
 
 Together, all three attributes of Trellis considerably lower the Total Cost of Ownership (TCO) for operators who plan to run it in production.
 
+.. note::
+    You can learn more about Trellis features and design concepts by visiting the `Project Website <https://opennetworking.org/trellis>`_ and
+    reading the `Platform Brief <https://www.opennetworking.org/wp-content/uploads/2019/09/TrellisPlatformBrief.pdf>`_.
+
 
 Highlights
 ==========
@@ -67,18 +71,13 @@
     .. image:: images/index-usecase-chassis.png
        :width: 600px
 
-
-Learn More
-==========
-- `Trellis Website <https://www.opennetworking.org/trellis>`_
-- `Trellis Platform Brief <https://www.opennetworking.org/wp-content/uploads/2019/09/TrellisPlatformBrief.pdf>`_
-
 .. toctree::
    :maxdepth: 1
    :hidden:
    :caption: Table of Contents
 
    architecture
+   specification
    supported-hardware
    installation
    configuration