docs(readme): move to docs/ directory and apply common structure

Author: myii

README.rst renamed to docs/README.rst

@@ -1,16 +1,54 @@
-==============
+.. _readme:
+
 zabbix-formula
 ==============
 
-A saltstack formula to manage Zabbix.
+|img_travis| |img_sr|
+
+.. |img_travis| image:: https://travis-ci.com/saltstack-formulas/zabbix-formula.svg?branch=master
+   :alt: Travis CI Build Status
+   :scale: 100%
+   :target: https://travis-ci.com/saltstack-formulas/zabbix-formula
+.. |img_sr| image:: https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg
+   :alt: Semantic Release
+   :scale: 100%
+   :target: https://github.com/semantic-release/semantic-release
+
+A SaltStack formula to manage Zabbix.
+
+.. contents:: **Table of Contents**
+
+General notes
+-------------
+
+See the full `SaltStack Formulas installation and usage instructions
+<https://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html>`_.
+
+If you are interested in writing or contributing to formulas, please pay attention to the `Writing Formula Section
+<https://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html#writing-formulas>`_.
+
+If you want to use this formula, please pay attention to the ``FORMULA`` file and/or ``git tag``,
+which contains the currently released version. This formula is versioned according to `Semantic Versioning <http://semver.org/>`_.
+
+See `Formula Versioning Section <https://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html#versioning>`_ for more details.
+
+Contributing to this repo
+-------------------------
+
+**Commit message formatting is significant!!**
+
+Please see :ref:`How to contribute <CONTRIBUTING>` for more details.
+
+Overview
+--------
 
 This formula has been developed distributing declarations in different files to
 make it usable in most situations. It should be useful in scenarios ranging from
 a simple install of the packages (without any special configuration) to a more
 complex set-up with different nodes for agent, server, database and frontend.
 
 Customization
-=============
+^^^^^^^^^^^^^
 
 First, **see if providing pillar data is enough for your customization needs**.
 That's the recommended way and should be enough for most cases. See that
@@ -27,7 +65,7 @@ recommended– to use other formulas to provision other parts of a complete
 system).
 
 Using RedHat EPEL repo Zabbix packages
-======================================
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 If you want to use the EPEL repo packages, as the naming conventions are
 different, you need to tweak the default values of ``map.jinja`` to obtain the
@@ -51,7 +89,7 @@ desired results. In short:
 Now you just have to use ``zabbix.agent.conf`` sls file and that's it.
 
 Example of usage
-================
+^^^^^^^^^^^^^^^^
 
 Just as an example, this is a ``top.sls`` file to install a complete modular
 self-contained Zabbix system:
@@ -110,105 +148,151 @@ pillar files
     <http://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html>`_ doc.
 
 Available states
-================
+----------------
 
 .. contents::
     :local:
 
 ``zabbix.agent``
-----------------
+^^^^^^^^^^^^^^^^
 
 Installs the zabbix-agent package and starts the associated zabbix-
 agent service.
 
 ``zabbix.agent.conf``
----------------------
+^^^^^^^^^^^^^^^^^^^^^
 
 Configures the zabbix-agent package.
 
 ``zabbix.agent.repo``
----------------------
+^^^^^^^^^^^^^^^^^^^^^
 
 Configures official Zabbix repo specifically for the agent. Actually it just
 includes zabbix.repo and adds a requisite for the pkg state declaration
 
 ``zabbix.frontend``
--------------------
+^^^^^^^^^^^^^^^^^^^
 
 Installs Zabbix frontend.
 
 ``zabbix.frontend.conf``
-----------------------
+^^^^^^^^^^^^^^^^^^^^^^^^
 
 Configures the zabbix-frontend package. Actually you need to use other formulas
 for apache/nginx and php5-fpm to complete a working setup.
 
 ``zabbix.frontend.repo``
-----------------------
+^^^^^^^^^^^^^^^^^^^^^^^^
 
 Configures official Zabbix repo specifically for the frontend. Actually it just
 includes zabbix.repo and adds a requisite for the pkg state declaration.
 
 ``zabbix.mysql.conf``
-----------------
+^^^^^^^^^^^^^^^^^^^^^
 
 Creates database and mysql user for Zabbix.
 
 ``zabbix.mysql.schema``
----------------------
+^^^^^^^^^^^^^^^^^^^^^^^
 
 Creates mysql schema for Zabbix.
 
 ``zabbix.pgsql.conf``
-----------------
+^^^^^^^^^^^^^^^^^^^^^
 
 Creates database and PostgreSQL user for Zabbix.
 
 ``zabbix.pgsql.schema``
----------------------
+^^^^^^^^^^^^^^^^^^^^^^^
 
 Creates PostgreSQL schema for Zabbix.
 
 ``zabbix.proxy``
-----------------
+^^^^^^^^^^^^^^^^
 
 Installs the zabbix-proxy package and starts the associated zabbix-proxy service.
 
 ``zabbix.proxy.conf``
----------------------
+^^^^^^^^^^^^^^^^^^^^^
 
 Configures the zabbix-proxy package.
 
 ``zabbix.proxy.repo``
----------------------
+^^^^^^^^^^^^^^^^^^^^^
 
 Configures official Zabbix repo specifically for the proxy. Actually it just
 includes zabbix.repo and adds a requisite for the pkg state declaration
 
 ``zabbix.repo``
-----------------
+^^^^^^^^^^^^^^^
 
 Configures official Zabbix repo.
 
 ``zabbix.server``
------------------
+^^^^^^^^^^^^^^^^^
 
 Installs the zabbix-server package and starts the associated zabbix-
 server service.
 
 ``zabbix.server.conf``
-----------------------
+^^^^^^^^^^^^^^^^^^^^^^
 
 Configures the zabbix-server package.
 
 ``zabbix.server.repo``
-----------------------
+^^^^^^^^^^^^^^^^^^^^^^
 
 Configures official Zabbix repo specifically for the server. Actually it just
 includes zabbix.repo and adds a requisite for the pkg state declaration
 
 ``zabbix.users``
-----------------
+^^^^^^^^^^^^^^^^
 
 Declares users and groups that could be needed in other formulas (e.g. in the
 users formula to make an user pertain to the service group).
+
+
+Testing
+-------
+
+Linux testing is done with ``kitchen-salt``.
+
+Requirements
+^^^^^^^^^^^^
+
+* Ruby
+* Docker
+
+.. code-block:: bash
+
+   $ gem install bundler
+   $ bundle install
+   $ bin/kitchen test [platform]
+
+Where ``[platform]`` is the platform name defined in ``kitchen.yml``,
+e.g. ``debian-9-2019-2-py3``.
+
+``bin/kitchen converge``
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Creates the docker instance and runs the ``template`` main state, ready for testing.
+
+``bin/kitchen verify``
+^^^^^^^^^^^^^^^^^^^^^^
+
+Runs the ``inspec`` tests on the actual instance.
+
+``bin/kitchen destroy``
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Removes the docker instance.
+
+``bin/kitchen test``
+^^^^^^^^^^^^^^^^^^^^
+
+Runs all of the stages above in one go: i.e. ``destroy`` + ``converge`` + ``verify`` + ``destroy``.
+
+``bin/kitchen login``
+^^^^^^^^^^^^^^^^^^^^^
+
+Gives you SSH access to the instance for manual testing.