Automatic PDM support

**Is your feature request related to a problem? Please describe.**
[PDM](https://github.com/pdm-project/pdm) folders are not recognized automatically

**Describe the solution you'd like**
PDM folders to be recognized automatically

**Describe alternatives you've considered**
Manually modifying site path

**Additional context**
see https://github.com/Almenon/AREPL-vscode/discussions/419
