Support local virtual environment creation

[mcdevitts]

Would it be possible to support the creation of a virtual environment in the project folder?

pdm-venv allows for easy install and cleanup of virtual environments as well as activation. It would be handy in some cases to create the virtual environment in the project directory.

Thanks for the great work! I've been enjoying pdm and pdm-venv.

[frostming]

What should be the name of venv?

1. If you prefer common names like .venv, venv, just create it via virtualenv tools and pdm can detect them.
2. If you want the name picked by pdm-venv, just point venv.location to the project root(project-wide) should work.

[Indiana3714]

Is there a simple GLOBAL setting for pdm/pdm-venv "venv.location" to point to the local directory? (ie so it works automatically when creating NEW projects, just like poetry) The readme on https://github.com/pdm-project/pdm-venv says "Available in Project = No", which doesnt seem to match what I'm/we're looking for?