Update to README needed for building?

[rkiddy]

Tried following the "or manually from source" procedure (modified to use virtualenv):

git clone https://github.com/openfoodfacts/openfoodfacts-python
cd openfoodfacts-python
virtualenv .venv
./.venv/bin/python setup.py install
Traceback (most recent call last):
  File "/home/ray/Projects/openfoodfacts-python/setup.py", line 1, in <module>
    import setuptools  # type: ignore
    ^^^^^^^^^^^^^^^^^
ModuleNotFoundError: No module named 'setuptools'

I do not find a setuptools.py anywhere in any OFF repo.

Any suggestions?