https://docs.python.org/3/library/venv.html nowhere explicitly states
how you are supposed to get a venv with a particular python version.
Users of virtualenv will be looking for a -p option.

The doc says:

"Creation of virtual environments is done by executing the pyvenv script:"

which undoubtably works if you _have_ a pyenv script, but I don't have
one.  It is nowhere stated where I should find one.

Fortunately, I can also run things as

some_python_version -m venv myvenv 

This, everybody is able to do.  (However, it may not work, see
issue 25151 --  but forget that for now.)

This is something that everybody ought to be able to do.
Thus I propose either deleting the mention of pyenv, (if it is exactly
equivalent to running python -m venv)  or expanding
the section, indicating where the script lives, and why you might
want to run it instead of python -m venv.

Then, before the line:
The command, if run with -h, will show the available options:

add the line:

The version of python used in the venv is determined at this time.
If the default version of python is not the one desired, use:

/path/to/the/python/I/want -m venv  myenv instead.

(Plus, if there is a way to do this with pyenv, then list that
part here).