Define *posix_venv* and *nt_venv*
:ref:`sysconfig installation schemes <installation_paths>`
to be used for bootstrapping new virtual environments.
Add *venv* sysconfig installation scheme to get the appropriate one of the above.
The schemes are identical to the pre-existing
*posix_prefix* and *nt* install schemes.
The :mod:`venv` module now uses the *venv* scheme to create new virtual environments
instead of hardcoding the paths depending only on the platform. Downstream
Python distributors customizing the *posix_prefix* or *nt* install
scheme in a way that is not compatible with the install scheme used in
virtual environments are encouraged not to customize the *venv* schemes.
When Python itself runs in a virtual environment,
:func:`sysconfig.get_default_scheme` and
:func:`sysconfig.get_preferred_scheme` with ``key="prefix"`` returns
*venv*.
