docs.voltha.org::HOWTO edits and WARNING cleanups.

Makefile
--------
  o Added convenience target 'make warnings' to help search for problems.

config.py
---------
  o Add more exclusions for .venv/ so sphinx will stop checking sources.

howto/edit_voltha_docs.rts
howto/docs.voltha.org/index.rst
howto/docs.voltha.org/quickstart.rst
howto/docs.voltha.org/edit_voltha_docs.rst
------------------------------------------
  o Added a quickstart guide for editing repo:voltha-docs

Misc
----
  o Fixed several WARNINGS
  o Add missing documents in index.rst

Change-Id: I0b3d01cc4116d40bd84db49649669253d6135546
diff --git a/howto/docs.voltha.org/edit_voltha_docs.rst b/howto/docs.voltha.org/edit_voltha_docs.rst
new file mode 100644
index 0000000..a5d8009
--- /dev/null
+++ b/howto/docs.voltha.org/edit_voltha_docs.rst
@@ -0,0 +1,114 @@
+Modify docs.voltha.org
+======================
+
+Docs for VOLTHA can be found on the website or via web search
+"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+- https://docs.voltha.org
+- https://docs.voltha.org/master/index.html
+
+   - Note: Google search may return an older doc version for topics.
+   - Navigate to /master/index.html and use the builtin searchbox to always view current documentation for VOLTHA.
+
+Browse repository content
+"""""""""""""""""""""""""
+- :vol-ger:`voltha-docs`
+- :vol-git:`voltha-docs`
+
+Documentation Guide
+===================
+
+Building the Docs
+"""""""""""""""""
+
+Building requires python, creates a virtualenv (``.venv``) which has all the
+necessary tools.
+
+Run ``make html`` to generate html documentation in ``_build/html``.
+
+Run ``make reload`` to get a live reload in your browser (refreshes on document
+save).
+
+Run ``make latexpdf`` to generate html documentation in ``_build/latex``.
+Requires that you have a recent LaTeX installation and ``latexmk`` installed
+
+Writing Docs
+""""""""""""
+
+Docs written using sphinx: https://www.sphinx-doc.org/en/master/
+
+Documentation is done in reStructuredText or Markdown, but only ``.rst`` files
+can contain embedded diagrams.
+
+Guides for RST:
+
+- https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html
+- https://www.sphinx-doc.org/en/master/usage/restructuredtext/index.html
+
+RST has multiple heading formats possible, the ones we're using are in the
+order for the HTML h1-h5: ``=``, ``-`` ``"``, ``'``, ``^``.
+
+
+Checkout, modify and test
+"""""""""""""""""""""""""
+
+.. sourcecode:: shell
+
+   $ git clone ssh://gerrit.opencord.org:29418/voltha-docs
+
+   $ cd voltha-docs
+   $ vi *.rst
+   $ make html           # doc generation
+   $ make lint           # syntax checking
+   $ make test           # syntax check *.rst files
+   $ make docs           # generate website pages
+
+   $ "$BROWSER" _build/html/index.html  # BROWSER='firefox'
+
+
+Interactive editing: real time updates
+""""""""""""""""""""""""""""""""""""""
+
+Another useful convenience makefile target to try is the reload target.
+"make reload" will invoke the sphinx-reload program, spawn a web page for
+viewing html documentation pages followed by periodic regeneration of page
+content.
+
+.. sourcecode:: shell
+
+   $ git clone ssh://gerrit.opencord.org:29418/voltha-docs
+
+   $ cd voltha-docs
+   $ make reload
+   $ vi *.rst
+
+
+make lint (syntax checking)
+"""""""""""""""""""""""""""
+- `make help (pending) <https://gerrit.opencord.org/c/voltha-system-tests/+/33306>`
+
+.. sourcecode:: shell
+
+   $ make help
+   $ USAGE: make target [, target(s)]
+   $
+   $ [LINT]
+   $  lint-json            Syntax check json sources
+   $  lint-python          Syntax check using pylint and flake8
+   $  lint-robot           Syntax check robot sources using rflint
+   $  lint-yaml            Syntax check yaml source using yamllint
+   $
+   $ make lint
+
+
+make html
+"""""""""
+- Install python packages: sphinx, pylint, flake8
+- Invoke sphinx to generate documentation.
+
+
+See Also
+""""""""
+- `RST Markup Documentation <https://rstdoc.readthedocs.io/en/latest>`
+- `Sphinx Documentation <https://www.sphinx-doc.org/en/master>`
+- `RST Markup Specification <https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html>`
+- howto/docs.voltha/org/quickstart
diff --git a/howto/docs.voltha.org/index.rst b/howto/docs.voltha.org/index.rst
new file mode 100644
index 0000000..fffaf7d
--- /dev/null
+++ b/howto/docs.voltha.org/index.rst
@@ -0,0 +1,8 @@
+HOWTO: docs.voltha.org
+======================
+
+.. toctree::
+   :maxdepth: 1
+
+   quickstart
+   edit_voltha_docs
diff --git a/howto/docs.voltha.org/quickstart.rst b/howto/docs.voltha.org/quickstart.rst
new file mode 100644
index 0000000..25743fe
--- /dev/null
+++ b/howto/docs.voltha.org/quickstart.rst
@@ -0,0 +1,116 @@
+Quickstart Guide: Editing
+=========================
+
+Intent
+------
+
+This quickstart guide decribes how to modify and commit changes that will
+be visible on http://docs.voltha.org.
+
+Clone repo:voltha-docs
+----------------------
+
+.. code:: bash
+
+   # Clone repo:voltha-docs
+   git clone ssh://gerrit.opencord.org:29418/voltha-docs.git
+
+   # Create a developer branch
+   git checkout -b dev-joey
+
+.. code-block: shell-session
+   :linenos: 2
+
+   # Clone repo:voltha-docs
+   git clone ssh://gerrit.opencord.org:29418/voltha-docs.git
+
+   # Create a developer branch
+   git checkout -b dev-joey
+
+Repositories:
+`gerrit <https://gerrit.opencord.org/plugins/gitiles/voltha-docs>`_
+`github <https://github.com/opencord/voltha-docs>`_
+
+.. code-block: shell-session
+   :linenos: 2,5
+
+   # Clone repo:voltha-docs
+   git clone ssh://gerrit.opencord.org:29418/voltha-docs.git
+
+   # Create a developer branch
+   git checkout -b dev-joey
+
+Interactive development
+-----------------------
+
+.. code-block: shell-session
+   :caption: Launch a browser for viewing local edits
+   :linenos: 4
+
+   cd voltha-docs
+   make reload
+
+- source edit: modify reStructuredText (RST) sources
+- Modify content to taste
+
+Invoke checkin tests locally
+----------------------------
+
+.. code-block: shell-session
+   :linenos: 3
+
+   cd voltha-docs
+   make sterile
+   make test
+
+.. list-table:: makefile targets for testing
+   :widths: 30,50
+   :header-rows: 2
+
+   * - make target
+     - Description
+   * -
+     -
+   * - make test
+     - Kitchen sink target: invokes all checkin tests (make lint linkcheck)
+   * - make lint
+     - Syntax check by source: rst, python
+   * - make linkcheck
+     - Verify URLs inlined within rst files are valid
+
+Document and commit changes for ``git log``
+-------------------------------------------
+
+.. code-block: shell-session
+   :linenos:
+
+   # Commit message: Line 1 symmarize changes with jira ticket linkage.
+   echo '[VOL-XXXX] update voltha.docs' > commit_message
+
+   # Commit message: Capture list of modified files
+   git status >> commit_message
+
+   # Commit message: Capture source diffs
+   git diff >> commit_message
+
+   # Summarize changes for git log
+   $EDIT commit_message
+
+   # git add <modified files>
+
+   # Commit changes to revision control
+   git commit -F commit_message
+
+   # Rebase your sandbox, merge branch=master into branch=dev-joey
+   ... git rebase documentation URL needed here ...
+
+   # Create a patch and request a code review
+   git review --reviewers email1 email2 email3
+
+Extra credit
+-------------------------------------------
+
+.. code-block: shell-session
+
+   make sterile
+   make html 2>&1 | sed -e 's/WARNING/\nWARNING/g' | less --ignore-case --hilite-search '/WARNING'