Docs: Restructuring and new layout

This patch implements a set of user-experiences aimed
changes.It modifies the documentation structure and
switches to a more reactive design for the rtd theme.

* The documentation layout has been redesigned to be more
  intuitive,easier to maintain and and scale.
* The landing page introduces a new dashboard.
* Introduced dedicated space for release documents, and
  changelog has been modified to directly source content
  from referenced documents.
* Added quick-link navigation for items that need emphasis.
* Relevant design documents can now be grouped in suf-folders.
* There is dedicated space for custom platform, and third
  party tools documents.
* Wildcard and regex matching has been introduced to indexes.

Change-Id: Ib02d17d5d26187d397ba17317788cf2a01401b07
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/docs/index.rst b/docs/index.rst
index f360584..06bfdcd 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -8,40 +8,97 @@
 
    The values between @ characters will be filled in by CMake.
 
-
 Trusted Firmware-M Documentation
 ================================
 
+.. raw:: html
+
+    <ul class="grid">
+        <li class="grid-item">
+            <a href="docs/introduction/readme.html">
+                <img alt="" src="_static/images/tfm.png"/>
+                <h2>Introduction</h2>
+            </a>
+            <p>Introducing the Trusted Firmware-M Project: overview,
+               architecture, features, and licensing</p>
+        </li>
+        <li class="grid-item">
+            <a href="docs/getting_started/index.html">
+               <img alt="" src="_static/images/tfm.png"/>
+               <h2>Getting Started Guides</h2>
+            </a>
+            <p>Follow this guide to set up a development environment on your
+               system, and then build and run a sample application.</p>
+        </li>
+        <li class="grid-item">
+            <a href="docs/contributing/index.html">
+                <img alt="" src="_static/images/tfm.png"/>
+                <h2>Contribution Guidelines</h2>
+            </a>
+            <p>As an open-source project, we welcome and encourage the community
+               to submit patches directly to the project.</p>
+        </li>
+        <li class="grid-item">
+            <a href="docs/reference/index.html">
+                <img alt="" src="_static/images/tfm.png"/>
+                <h2>References</h2>
+            </a>
+            <p>User guides, API Documentation, interfaces</p>
+        </li>
+        <li class="grid-item">
+            <a href="docs/design_documents/index.html">
+                <img alt="" src="_static/images/tfm.png"/>
+                <h2>Design</h2>
+            </a>
+            <p>Design documents, threat models.</p>
+        </li>
+        <li class="grid-item">
+            <a href="platform/ext/index.html">
+                <img alt="" src="_static/images/tfm.png"/>
+                <h2>Platforms</h2>
+            </a>
+            <p>List of supported boards and platforms.</p>
+        </li>
+        <li class="grid-item">
+            <a href="https://ci.trustedfirmware.org/job/tf-m-build-docs/lastSuccessfulBuild/artifact/trusted-firmware-m/build/install/doc/reference_manual/html/index.html">
+                <img alt="" src="_static/images/tfm.png"/>
+                <h2>API</h2>
+            </a>
+            <p>Doxygen documentation.</p>
+        </li>
+        <li class="grid-item">
+        <a href="https://developer.arm.com/architectures/security-architectures/platform-security-architecture">
+            <img alt="" src="_static/images/tfm.png"/>
+            <h2>PSA</h2>
+        </a>
+        <p>Platform Security Architecture (PSA) information.</p>
+        </li>
+    </ul>
+
 .. toctree::
-    :maxdepth: 2
+    :caption: Table of Contents
+    :name: mastertoc
+    :titlesonly:
+    :maxdepth: 1
     :hidden:
 
-    Home<docs/readme>
-    docs/about/index
-    docs/changelog
+    Home<self>
+    docs/introduction/index
+    docs/getting_started/index
+    docs/contributing/index
+    docs/reference/index
     docs/design_documents/index
-    docs/user_guides/index
-    docs/processes/index
-    docs/glossary
-    docs/lic
+    platform/ext/index
+
 
 .. toctree::
-    :caption: Target platforms
     :maxdepth: 2
-    :glob:
     :hidden:
+    :caption: Quick Links
 
-    platform/**
-
-.. toctree::
-    :caption: Tools
-    :maxdepth: 2
-    :glob:
-    :hidden:
-
-    tools/iat-verifier/*
-
-.. include:: docs/readme.rst
+    docs/reference/changelog
+    docs/reference/glossary
+    docs/contributing/lic
 
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