Add sphinx doc build with tox

* Add basic doc build system with sphinx and tox
* Update README.md for how-to build docs
* Update .gitignore to exclude docs builds
* Add index and move README for Noop tests framework
* TODO split and add more details for how-to noop tests
  setup/use/create

Inspired by https://github.com/openstack/openstack-manuals

Partial-bug: #1483288

Change-Id: I982e0baaff5de95c7d0c4b3f098754a80676f0d0
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

README.md

@@ -8,9 +8,10 @@
 3. [Granular Deployment - What is the granular deployment for Fuel?](#granular-deployment)
 4. [Upstream Modules - How to work with librarian.](#upstream-modules)
 5. [Testing - How to run fuel-library tests.](#testing)
-6. [Development](#development)
-7. [Core Reviers](#core-reviewers)
-8. [Contributors](#contributors)
+6. [Building docs - How to build docs.](#build-docs)
+7. [Development](#development)
+8. [Core Reviers](#core-reviewers)
+9. [Contributors](#contributors)
 
 ## Overview
 -----------
@@ -32,6 +33,7 @@ fuel-library
 ├── MAINTAINERS
 ├── debian
 ├── deployment
+├── doc
 ├── files
 ├── specs
 ├── tests
@@ -61,6 +63,11 @@ This folder contains the fuel-library Puppet code, the Puppetfile for
 upstream modules, and scripts to manage modules with
 [librarian-puppet-simple](https://github.com/bodepd/librarian-puppet-simple).
 
+### doc/
+
+This folder contains RST docs. Currently there is only docs for Noop testing
+framework.
+
 ### files/
 
 This folder contains scripts and configuration files that are used when
@@ -107,6 +114,32 @@ quality. The fuel-library leverages existing Puppet module rspec tests,
 [bats](https://github.com/sstephenson/bats) tests for bash scripts and noop
 tests for testing the module deployment tasks in fuel-library.
 
+## Building docs
+----------------
+
+You can use tox to prepare virtual environment and build
+all RST based guides:
+
+    tox -e docs
+
+You can also build a specific guide. For example, to build *Noop Tests
+How-to Guide*, use the following command:
+
+    tox -e build -- noop-guide
+
+You can find the root of the generated HTML documentation at:
+
+    ./doc/noop-guide/build/html/index.html
+
+You can also run docs tests with `tox`.
+If you like to run individual tests, run:
+
+> -   `tox -e checkniceness` - to run the niceness tests
+> -   `tox -e checksyntax` - to run syntax checks
+
+tox will use the openstack-doc-tools package for execution of these
+tests.
+
 ### Puppet module tests
 
 Puppet rspec tests should be provided for an every module's directory included.