[docs] [issue22394] Update documentation building to use venv and pip

[Tshepang Lekhonkhobe]

Changes by Tshepang Lekhonkhobe <tshepang at gmail.com>:


----------
nosy: +tshepang

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue22394>
_______________________________________