doc: De-duplicate readme and license files ...

The readme.rst and license.rst files in the project root overlap
with the index.rst and license.rst files in the docs/ folder. We
need to use the latter when building the documentation, as Sphinx
requires all included files to be under a common root. However,
the files in the root are currently used by the cgit and Github
viewers.

Using symlinks in Git presents some difficulties so the best
course of action is likely to leave these files but in stub form.

The license.rst file in the root will simply tell the reader to
refer to docs/license.rst.

The readme.rst file will contain a small amount of content that
is derived from the docs/index.rst file, so that the Github main
page will have something valid to show, but it will also contain
a link to the full documentation on ReadTheDocs.

Change-Id: I6dc46f08777e8d7ecb32ca7afc07a28486c9f77a
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

doc: Use proper note and warning annotations ...

The documentation contains plenty of notes and warnings. Enable
special rendering of these blocks by converting the note prefix
into a .. note:: annotation.

Change-Id: I34e26ca6bf313d335672ab6c2645741900338822
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

Change copyright guidelines ...

Copyright guidance has been changed for migration of the
ARM run project to trustedfirmware.org where the project
governance is different.

Change-Id: I059177453fb357843eced93c2a55b3705a379683
Signed-off-by: Joanna Farley <joanna.farley@arm.com>

Update Arm TF references to TF-A ...

Update Arm Trusted Firmware references in the upstream documents to
Trusted Firmware-A (TF-A). This is for consistency with and
disambiguation from Trusted Firmware-M (TF-M).

Also update other Arm trademarks, e.g. ARM->Arm, ARMv8->Armv8-A.

Change-Id: I8bb0e18af29c6744eeea2dc6c08f2c10b20ede22
Signed-off-by: Dan Handley <dan.handley@arm.com>
Signed-off-by: David Cunado <david.cunado@arm.com>

Convert documentation to reStructuredText ...

Due to recent issues in the rendering of the documentation on GitHub and
some long-standing issues like the lack of automatic table of content in
Markdown, the documentation has been converted to reStructuredText.
Basic constructs looks pretty similar to Markdown.

Automatically convert GitHub markdown documentation to reStructuredText
using pandoc.

Change-Id: If20b695acedc6d1b49c8d9fb64efd6b6ba23f4a9
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>