docs: refresh & structure overhaul

Rework the doc in order to improve the navigation experience and to make
it easier to update the doc:

- simplify structure: docs/{release-notes,user,developer}
- recreate sphinx config file
- switch theme from opnfv to piccolo
- fix minor rst issues
- fix external references
- add missing license headers (add a short header with copyright and
  SPDX license identifier to the files lacking the information.  The
  header is based on https://github.com/david-a-wheeler/spdx-tutorial)

Change-Id: I9a1135a2873d9955beb26760e0cb6c5d6c1326bd
Signed-off-by: Gwenael Lambrouin <gwenael.lambrouin@orange.com>

1 files changed, 0 insertions, 89 deletions

diff --git a/docs/testing/developer/devguide/testing-nfvbench.rst b/docs/testing/developer/devguide/testing-nfvbench.rst
deleted file mode 100644
index 3e53d08..0000000
--- a/docs/testing/developer/devguide/testing-nfvbench.rst
+++ /dev/null
@@ -1,89 +0,0 @@
-.. This work is licensed under a Creative Commons Attribution 4.0 International License.
-.. SPDX-License-Identifier: CC-BY-4.0
-
-================
-Testing NFVbench
-================
-
-tox
-===
-
-NFVbench project uses `tox`_ to orchestrate the testing of the code base:
-
-* run unit tests
-* check code style
-* run linter
-* check links in the docs
-
-In addition to testing, tox is also used to generate the documentation in HTML
-format.
-
-What tox should do is specified in a ``tox.ini`` file located at the project root.
-
-tox is used in continuous integration (jenkins-ci today, gitlab-ci in the near
-future): all the actions performed by tox must succeed before a patchset can be
-merged.  As a developer, it is also useful to run tox locally to detect and fix
-the issues before pushing the code for review.
-
-.. _tox: https://tox.readthedocs.io/en/latest/
-
-
-
-Using tox on a developer's machine
-==================================
-
-Requirement: |python-version|
------------------------------
-
-.. |python-version| replace:: Python 3.6
-
-The current version of Python used by NFVbench is |python-version|.  In
-particular, this means that |python-version| is used:
-
-* by tox in CI
-* in nfvbench Docker image
-* in nfvbench traffic generator VM image
-
-|python-version| is needed to be able to run tox locally.  If it is not
-available through the package manager, it can be installed using `pyenv`_.  In
-that case, it will also be necessary to install the `pyenv-virtualenv`_ plugin.
-Refer to the documentation of those projects for installation instructions.
-
-.. _pyenv: https://github.com/pyenv/pyenv
-.. _pyenv-virtualenv: https://github.com/pyenv/pyenv-virtualenv
-
-
-tox installation
-----------------
-
-Install tox with::
-
-    $ pip install tox tox-pip-version
-
-
-Running tox
------------
-
-In nfvbench root directory, simply run tox with::
-
-    $ tox
-
-If all goes well, tox shows a green summary such as::
-
-    py36: commands succeeded
-    pep8: commands succeeded
-    lint: commands succeeded
-    docs: commands succeeded
-    docs-linkcheck: commands succeeded
-    congratulations :)
-
-It is possible to run only a subset of tox *environments* with the ``-e``
-command line option.  For instance, to check the code style only, do::
-
-    $ tox -e pep8
-
-Each tox *environment* uses a dedicated python virtual environment.  The
-``-r`` command line option can be used to force the recreation of the virtual
-environment(s).  For instance::
-
-    $ tox -r