Inconsistency of used documentation tools: `Sphinx` vs `mkdocs`

[anates]

In the given pyproject.toml-file sphinx is used for generating documentation:

docs = [
  "sphinx==4.2.0",
  "sphinx-rtd-theme==1.0.0",
]

Later, however, during the documentation examples, mkdocs is used instead:

We will focus on MkDocs as it is easier to use and provides most of the functionality that we need.

As this is not among the requirements defined earlier, running mkdocs with the command given in the notebook

mkdocs serve --dev-addr=0.0.0.0:8000

Proposed solution:
Adding mkdocs instead of sphinx in pyproject.toml, or running pip install mkdocs in addition.