[docs] [issue32553] venv says to use python3 which does not exist in 3.6.4

Eryk Sun <eryksun@gmail.com> added the comment: `PATHEXT` is irrelevant here, so that should be removed. As to the py launcher, it's optional and not always installed for all users, though that's the default. I'd prefer `python` that's found in PATH as the first example. Then add another example with `py -X.Y` to show how to create virtual environments for other versions. ---------- nosy: +eryksun _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue32553> _______________________________________