Documentation: Add documentation-contents.rst

Add a new .rst file referencing the documentation contents. This file
is then included in each documentation page so that we can enhance
the Documentation pages on the libcamera website using it. As we do
not want the appearance of the libcamera in-tree Documentation to
change just yet, disable the new class using the sphinx theme's CSS.

To facilitate easier distinguishing between "normal" and
documentation pages on the website we want to add a "documentation"
class to the content of all such pages. Since this new file will be
included on each documentation page it is convenient to add the new
directive here - do so. As the website uses different CSS to
libcamera, move the contents on docs.rst a little so that the
directive at the end of the contents block applies correctly.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Documentation/documentation-contents.rst

@@ -0,0 +1,27 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. container:: documentation-nav
+
+   * :doc:`/api-html/index`
+   * :doc:`/camera-sensor-model`
+   * :doc:`/code-of-conduct`
+   * :doc:`/coding-style`
+   * :doc:`/environment_variables`
+   * :doc:`/guides/application-developer`
+   * :doc:`/guides/introduction`
+   * :doc:`/guides/ipa`
+   * :doc:`/guides/pipeline-handler`
+   * :doc:`/guides/tracing`
+   * :doc:`/lens_driver_requirements`
+   * :doc:`/python-bindings`
+   * :doc:`/sensor_driver_requirements`
+   * :doc:`/software-isp-benchmarking`
+
+..
+   The following directive adds the "documentation" class to all of the pages
+   generated by sphinx. This is not relevant in libcamera nor addressed in the
+   theme's CSS, since all of the pages here are documentation. It **is** used
+   to properly format the documentation pages on libcamera.org and so should not
+   be removed.
+
+.. rst-class:: documentation