DOC: update documentation.

Add documentation covering:
  - developer information about architecture
  - project structure and building
  - project overview and service descriptions
  - the portability model for supporting hardware

Signed-off-by: Julian Hall <julian.hall@arm.com>
Co-Authored-By: Gyorgy Szing <gyorgy.szing@gmail.com>
Change-Id: I8bf9c01a66350719d82a7ca2bc1c78a8ab17978d
diff --git a/tools/b-test/Readme.rst b/tools/b-test/Readme.rst
index 4100e91..a4ec2c4 100644
--- a/tools/b-test/Readme.rst
+++ b/tools/b-test/Readme.rst
@@ -96,8 +96,6 @@
 
 --------------
 
-*Copyright (c) 2020, Arm Limited and Contributors. All rights reserved.*
-
 .. |yasha| replace:: `yasha`_
 .. |jinja2| replace:: `Jinja2`_
 .. |yaml| replace:: `yaml`_
@@ -105,3 +103,7 @@
 .. _Jinja2: https://palletsprojects.com/p/jinja
 .. _yasha: https://github.com/kblomqvist/yasha
 .. _yaml: https://yaml.org
+
+*Copyright (c) 2020-2021, Arm Limited and Contributors. All rights reserved.*
+
+SPDX-License-Identifier: BSD-3-Clause
\ No newline at end of file