Added sphinx requirements to pyproject.toml (#1279)

* Added Sphinx dependencies to pyproject.toml

* Updated documentation

* Updates poetry.lock

Co-authored-by: Benjamin Hackl <[email protected]>

Author: jsonvillanueva

docs/source/contributing/development.rst

@@ -212,8 +212,7 @@ sticks to our coding conventions.
   to your pull request. Make sure not to introduce any Sphinx errors, and have
   a look at the built HTML files to see whether the formatting of the documentation
   you added looks like you intended. You can build the documentation locally
-  by running ``pip install -r docs/requirements.txt``
-  and then running ``make html``.
+  by running ``make html`` from the ``docs`` directory.
 
 Finally, if the pipeline passes and you are satisfied with your changes: wait for
 feedback and iterate over any requested changes. You will likely be asked to