fix: 🐛 fix missing dependencies for building sphinx docs

Author: newgene

docs/sphinx-requirements.txt

@@ -1,5 +1,5 @@
 # Requirements for virtualenv when building sphinx documentation
 #  using the dependencies specified in setup.py file
--e .[dev]
+-e .[web_extra,hub,cli,docker_ssh,dev,docs]
 #async-timeout==3.0.1    # solving a dependency issue under Python 3.7 (e.g. readthedocs)
 #                       # async-timeout is a dependency of elasticsearch-async