Building the docs breaks #100
Description
I noticed that building the docs locally on master fails due to the following error:
sphinx.errors.SphinxWarning: /python-storage/docs/index.rst:27:toctree contains reference to document 'changelog' that doesn't have a title: no link will be generated
It turns out that the issue does not occur with the older version of Sphinx (< 3.x), thus it appears as a bug in the Sphinx package itself. A workaround is to pin that dependency to an older version.