Update docs landing page to follow guideline

During the rocky cycle, there was a docs-spec approved [0] with the
goal of having a recommended consistent documentation landing page
for all projects.

This updates our docs landing page to follow the structure described
in that recommendation.

[0] http://specs.openstack.org/openstack/docs-specs/specs/rocky/front-page-template.html

Change-Id: Ie2d2a2c06ef0ffe32a80eac85313ab57020af5ba

doc/source/index.rst

@@ -15,10 +15,15 @@
       License for the specific language governing permissions and limitations
       under the License.
 
-Welcome to Manila's developer documentation!
-============================================
+===================================================
+OpenStack Shared Filesystems (manila) documentation
+===================================================
 
-Manila is an OpenStack project to provide "Shared Filesystems as a service".
+What is Manila?
+---------------
+
+Manila is the OpenStack Shared Filesystems service for providing Shared
+Filesystems as a service. Some of the goals of Manila are to be/have:
 
 * **Component based architecture**: Quickly add new behaviors
 * **Highly available**: Scale to very serious workloads
@@ -26,73 +31,118 @@ Manila is an OpenStack project to provide "Shared Filesystems as a service".
 * **Recoverable**: Failures should be easy to diagnose, debug, and rectify
 * **Open Standards**: Be a reference implementation for a community-driven api
 
-This documentation is generated by the Sphinx toolkit and lives in the source
-tree. Additional draft and project documentation on Manila and other components of OpenStack can
-be found on the `OpenStack wiki`_. Cloud administrators, refer to `docs.openstack.org`_.
+For end users
+-------------
 
-.. _`OpenStack wiki`: https://wiki.openstack.org
-.. _`docs.openstack.org`: https://docs.openstack.org
+As an end user of Manila, you'll use Manila to create a remote file system with
+either tools or the API directly:
+`python-manilaclient <https://docs.openstack.org/python-manilaclient/latest/>`_,
+or by directly using the
+`REST API <https://developer.openstack.org/api-ref/shared-file-system/>`_.
 
+Tools for using Manila
+~~~~~~~~~~~~~~~~~~~~~~
 
-
-Installing Manila
-=================
-
-.. toctree::
-   :maxdepth: 1
-
-   install/index
-
-Admin Docs
-==========
-
-.. toctree::
-   :maxdepth: 1
-
-   admin/index
-
-Contributor/Developer Docs
-==========================
-
-.. toctree::
-   :maxdepth: 1
-
-   contributor/index
-
-Command Line Interface Documentation
-====================================
-
-.. toctree::
-   :maxdepth: 1
-
-   cli/index
-
-
-Configuration Reference
-=======================
-
-.. toctree::
-   :maxdepth: 1
-
-   configuration/index
-
-Other Reference
-===============
-
-.. toctree::
-   :maxdepth: 1
-
-   reference/index
-
-User Documentaton
-=================
+Contents:
 
 .. toctree::
    :maxdepth: 1
 
    user/index
 
-Indices and tables
-==================
+Using the Manila API
+~~~~~~~~~~~~~~~~~~~~
+
+All features of Manila are exposed via a REST API that can be used to build
+more complicated logic or automation with Manila. This can be consumed directly
+or via various SDKs. The following resources can help you get started consuming
+the API directly:
+
+* `Manila API <https://developer.openstack.org/api-ref/shared-file-system/>`_
+* :doc:`Manila microversion history </contributor/api_microversion_history>`
+
+For operators
+-------------
+
+This section has details for deploying and maintaining Manila services.
+
+Installing Manila
+~~~~~~~~~~~~~~~~~
+
+Manila can be configured standalone using the configuration setting
+``auth_strategy = noauth``, but in most cases you will want to at least have
+the `Keystone <https://docs.openstack.org/keystone/latest/install/>`_ Identity
+service and other
+`OpenStack services <https://docs.openstack.org/latest/install/>`_ installed.
+
+.. toctree::
+   :maxdepth: 1
+
+   install/index
+
+Administrating Manila
+~~~~~~~~~~~~~~~~~~~~~
+
+Contents:
+
+.. toctree::
+   :maxdepth: 1
+
+   admin/index
+
+Reference
+~~~~~~~~~
+
+Contents：
+
+.. toctree::
+   :maxdepth: 1
+
+   configuration/index
+   cli/index
+
+Additional resources
+~~~~~~~~~~~~~~~~~~~~
+
+* `Manila release notes <https://docs.openstack.org/releasenotes/manila/>`_
+
+For contributors
+----------------
+
+Contributions to Manila are welcome. There is a lot of background information that
+can help you get started. Please feel free to also ask any questions in
+the **#openstack-manila** IRC channel.
+
+Getting started
+~~~~~~~~~~~~~~~
+
+* `OpenStack Contributor Guide <https://docs.openstack.org/contributors/>`_
+
+Contributing to Manila
+~~~~~~~~~~~~~~~~~~~~~~
+
+Contents:
+
+.. toctree::
+   :maxdepth: 1
+
+   contributor/index
+   API Microversions </contributor/api_microversion_dev/>
+
+Additional reference
+~~~~~~~~~~~~~~~~~~~~
+
+Contents:
+
+.. toctree::
+   :maxdepth: 1
+
+   reference/index
+
+Additional reference
+~~~~~~~~~~~~~~~~~~~~
+
+Contents:
 
 * :ref:`genindex`
+