[Community goal] Update contributor documentation

As the Ussuri goal we have an OpenStack project wide contributing
documentation template [1]. pyhton-novaclient use its own bug or feature
tracking LP and core team is also not exactly same as nova  so adding
its own contributor guide with keeping common links from nova
with python-novaclient specific information.

Also the top level CONTRIBUTING.rst template has been changed in the
cookiecutter repo[2]. So this patch updates the CONTRIBUTING.rst according
to the new template.

[1] https://opendev.org/openstack/cookiecutter/src/branch/master/%7b%7bcookiecutter.repo_name%7d%7d/doc/source/contributor/contributing.rst
[2] https://review.opendev.org/#/c/696001

Change-Id: Idd35fdf54a92a4a000d0d7776884682c8722854b
Story: #2007236
Task: #38541

CONTRIBUTING.rst

@@ -1,16 +1,19 @@
-If you would like to contribute to the development of OpenStack,
-you must follow the steps documented at:
+The source repository for this project can be found at:
 
-   https://docs.openstack.org/infra/manual/developers.html#development-workflow
+   https://opendev.org/openstack/python-novaclient
 
-Once those steps have been completed, changes to OpenStack
-should be submitted for review via the Gerrit tool, following
-the workflow documented at:
+Pull requests submitted through GitHub are not monitored.
 
-   https://docs.openstack.org/infra/manual/developers.html#development-workflow
+To start contributing to OpenStack, follow the steps in the contribution guide
+to set up and use Gerrit:
 
-Pull requests submitted through GitHub will be ignored.
+   https://docs.openstack.org/contributors/code-and-documentation/quick-start.html
 
-Bugs should be filed on Launchpad, not GitHub:
+Bugs should be filed on Launchpad:
 
    https://bugs.launchpad.net/python-novaclient
+
+For more specific information about contributing to this repository, see the
+python-novaclient contributor guide:
+
+   https://docs.openstack.org/python-novaclient/latest/contributor/contributing.html

doc/source/contributor/contributing.rst

@@ -0,0 +1,52 @@
+============================
+So You Want to Contribute...
+============================
+
+For general information on contributing to OpenStack, please check out the
+`contributor guide <https://docs.openstack.org/contributors/>`_ to get started.
+It covers all the basics that are common to all OpenStack projects: the accounts
+you need, the basics of interacting with our Gerrit review system, how we
+communicate as a community, etc.
+
+Below will cover the more project specific information you need to get started
+with python-novaclient.
+
+Communication
+~~~~~~~~~~~~~
+
+Please refer `how-to-get-involved <https://docs.openstack.org/nova/latest/contributor/how-to-get-involved.html>`_.
+
+Contacting the Core Team
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+The overall structure of the Nova team including python-novaclient is
+documented on `the wiki <https://wiki.openstack.org/wiki/Nova#People>`_.
+
+New Feature Planning
+~~~~~~~~~~~~~~~~~~~~
+
+If you want to propose a new feature please read the
+`blueprints <https://docs.openstack.org/nova/latest/contributor/blueprints.html>`_ page.
+
+Task Tracking
+~~~~~~~~~~~~~
+
+We track our tasks in `Launchpad <https://bugs.launchpad.net/python-novaclient>`__.
+
+If you're looking for some smaller, easier work item to pick up and get started
+on, search for the 'low-hanging-fruit' tag.
+
+Reporting a Bug
+~~~~~~~~~~~~~~~
+
+You found an issue and want to make sure we are aware of it? You can do so on
+`Launchpad <https://bugs.launchpad.net/python-novaclient/+filebug>`__.
+More info about Launchpad usage can be found on `OpenStack docs page
+<https://docs.openstack.org/contributors/common/task-tracking.html#launchpad>`_.
+
+Getting Your Patch Merged
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+All changes proposed to the python-novaclient requires two ``Code-Review +2``
+votes from python-novaclient core reviewers before one of the core reviewers
+can approve patch by giving ``Workflow +1`` vote..

doc/source/contributor/index.rst

@@ -2,14 +2,16 @@
  Contributor Guide
 ===================
 
-Code is hosted at `opendev.org`__. Submit bugs to the python-novaclient
-project on `Launchpad`__. Submit code to the `openstack/python-novaclient`
-project using `Gerrit`__.
+Basic Information
+=================
 
-__ https://opendev.org/openstack/python-novaclient
-__ https://bugs.launchpad.net/python-novaclient
-__ https://docs.openstack.org/infra/manual/developers.html#development-workflow
+.. toctree::
+   :maxdepth: 2
 
+   contributing
+
+Developer Guide
+===============
 .. toctree::
    :maxdepth: 2