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/reference/index.rst b/docs/reference/index.rst
new file mode 100644
index 0000000..02c1077
--- /dev/null
+++ b/docs/reference/index.rst
@@ -0,0 +1,16 @@
+Reference
+=========
+
+.. toctree::
+    :maxdepth: 1
+    :glob:
+    :numbered:
+
+    changelog
+    glossary
+    */index
+    /tools/index
+
+--------------
+
+*Copyright (c) 2020, Arm Limited. All rights reserved.*