Improve the documentation about the new sections in the config file

[Crsi]

The new sections development and consumables in the config file don't have a description in the documentation yet. This should be added.
Additionally, the configuration file should not be pasted into the docs/source/config.rst file directly, it should rather be an import as in docs/source/database.rst, e.g.:

.. literalinclude:: config.json
    :language: json