sphinx: import docs

The Yocto Project docs was migrated from Docbook to Sphinx in YP
 3.2. This 3.1 is an LTS release, and since 3.1 docs are 'close to'
 the docs in 3.2, we agreed to backport sphinx docs onto 3.1.

This first patch brings all changes done in 3.2 until:
7f64574f7 README: include detailed information about sphinx

There are other changes after this commit, but they will be
 selectively backported in individual patches.

This patch was generated with the following command:

git cherry-pick -n \
 $(git log --reverse --oneline \
 ac352ad7f95db7eeacb53c2778caa31800bd7c26..7f64574f7 \
| cut -f1 -d' ')

The following commits were applies in the dunfell docs, but not in
master, so they were first reverted (and squashed into this change). A
commit will reintroduce the content from these patches in the Sphinx
files in a followup patch.

069c27574 Documenation: Prepared for the 3.1.1 release
bd140f0f9 Documentation: Add 3.1.1 version updates missing from previous commit
17cc71a8f Documenation: Prepared for the 3.1.2 release
1a69e2c02 Documenation: Prepared for the 3.1.3 release
8910ac1c7 Documenation: Prepared for the 3.1.4 release

(From yocto-docs rev: c25fe058b88b893b0d146f3ed27320b47cdec236)

Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 74 insertions, 0 deletions

diff --git a/documentation/overview-manual/overview-manual-intro.rst b/documentation/overview-manual/overview-manual-intro.rst
new file mode 100644
index 0000000000..3f206fd54b
--- /dev/null
+++ b/documentation/overview-manual/overview-manual-intro.rst
@@ -0,0 +1,74 @@
+.. SPDX-License-Identifier: CC-BY-2.0-UK
+
+**********************************************
+The Yocto Project Overview and Concepts Manual
+**********************************************
+
+.. _overview-manual-welcome:
+
+Welcome
+=======
+
+Welcome to the Yocto Project Overview and Concepts Manual! This manual
+introduces the Yocto Project by providing concepts, software overviews,
+best-known-methods (BKMs), and any other high-level introductory
+information suitable for a new Yocto Project user.
+
+The following list describes what you can get from this manual:
+
+-  `Introducing the Yocto Project <#overview-yp>`__\ *:* This chapter
+   provides an introduction to the Yocto Project. You will learn about
+   features and challenges of the Yocto Project, the layer model,
+   components and tools, development methods, the
+   :term:`Poky` reference distribution, the
+   OpenEmbedded build system workflow, and some basic Yocto terms.
+
+-  `The Yocto Project Development
+   Environment <#overview-development-environment>`__\ *:* This chapter
+   helps you get started understanding the Yocto Project development
+   environment. You will learn about open source, development hosts,
+   Yocto Project source repositories, workflows using Git and the Yocto
+   Project, a Git primer, and information about licensing.
+
+-  :doc:`overview-manual-concepts` *:* This
+   chapter presents various concepts regarding the Yocto Project. You
+   can find conceptual information about components, development,
+   cross-toolchains, and so forth.
+
+This manual does not give you the following:
+
+-  *Step-by-step Instructions for Development Tasks:* Instructional
+   procedures reside in other manuals within the Yocto Project
+   documentation set. For example, the :doc:`../dev-manual/dev-manual`
+   provides examples on how to perform
+   various development tasks. As another example, the 
+   :doc:`../sdk-manual/sdk-manual` manual contains detailed
+   instructions on how to install an SDK, which is used to develop
+   applications for target hardware.
+
+-  *Reference Material:* This type of material resides in an appropriate
+   reference manual. For example, system variables are documented in the
+   :doc:`../ref-manual/ref-manual`. As another
+   example, the :doc:`../bsp-guide/bsp-guide` contains reference information on
+   BSPs.
+
+-  *Detailed Public Information Not Specific to the Yocto Project:* For
+   example, exhaustive information on how to use the Source Control
+   Manager Git is better covered with Internet searches and official Git
+   Documentation than through the Yocto Project documentation.
+
+.. _overview-manual-other-information:
+
+Other Information
+=================
+
+Because this manual presents information for many different topics,
+supplemental information is recommended for full comprehension. For
+additional introductory information on the Yocto Project, see the
+:yocto_home:`Yocto Project Website <>`. If you want to build an image
+with no knowledge of Yocto Project as a way of quickly testing it out,
+see the :doc:`../brief-yoctoprojectqs/brief-yoctoprojectqs` document.
+For a comprehensive list of links and other documentation, see the
+":ref:`Links and Related
+Documentation <resources-links-and-related-documentation>`"
+section in the Yocto Project Reference Manual.