v0.5.0 - rename package to pimmslearn

The package is called pimms-learn (similar to scikit-learn) on PyPI, but is no imported
as pimmslearn (similar to sklearn). The documentation (README and on PyPI) no features a simple usage of the
scikit-learn like Transformer classes.

What's Changed

• Rename pkg from vaep to pimmslearn by @enryH in #74
• Rename pkg by @enryH in #75

Full Changelog: v0.4.2...v0.5.0