added .py to end of cli command

[shimwell]

Description

Not ready to merge

I've found an issue making a conda forge package when the command line script has no file extension. So this PR changes the command line script to have a .py extension

Checklist

• [x] I'm making a PR from a feature branch on my fork into GEOUNED-org/GEOUNED/dev branch
• [x] I have followed PEP8 style guide for Python or run a formatter such as black or ruff format on my code
• [x] I have made corresponding changes to the documentation
• [x] I have added tests that prove my fix is effective or that my feature works

[shimwell]

closing as extensions are not supported in the pyproject.toml