API documentation guide

Guide how to use Swagger and swaggerv2dcc directive
Add 2 JSON Swagger files
Add code block

Change-Id: If3af3f20509db2cc47bdb2cf3db9b44d8a1bcdc7
Issue-ID: DOC-426
Signed-off-by: Eric Debeau <eric.debeau@orange.com>
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+.. This work is licensed under a Creative Commons Attribution 4.0
+.. International License. http://creativecommons.org/licenses/by/4.0
+.. Copyright 2019 Orange.  All rights reserved.
+
+.. _api-swagger-guide:
+
+API documentation
+=================
+
+Swagger
+-------
+
+The API should be described using OpenAPI specifications and available as a
+`JSON file <https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md>`_
+
+A Swagger editor is available here `<http://editor.swagger.io/>`_ to generate
+such JSON files.
+
+As a result, you should get one JSON file per API:
+
+- myAPI1.json
+- myAPI2.json
+
+Global API table
+----------------
+It is recommended to list the following API available with an access to the
+Swagger JSON files to help the developers/users to play with JSON.
+
+We propose the following table:
+
+.. csv-table::
+   :header: "API name", "Swagger JSON"
+   :widths: 10,5
+
+   "myAPI1", ":download:`link <myAPI1.json>`"
+   "myAPI12", ":download:`link <myAPI2.json>`"
+
+
+The code is available here:
+
+.. code:: rst
+
+   ..csv-table::
+     :header: "API name", "Swagger JSON"
+     :widths: 10,5
+
+     "myAPI1", ":download:`link <myAPI1.json>`"
+     "myAPI2", ":download:`link <myAPI2.json>`"
+
+API Swagger
+-----------
+For each API, the ``swaggerv2doc`` directive must be used as follows:
+
+.. code:: rst
+
+   myAPI1
+   ......
+   .. swaggerv2doc:: myAPI1.json
+
+   myAPI2
+   ......
+   .. swaggerv2doc:: myAPI2.json
+
+It will produce the following output:
+
+myAPI1
+......
+.. swaggerv2doc:: myAPI1.json
+
+myAPI2
+......
+.. swaggerv2doc:: myAPI2.json