Pyoptex

Replaced np.int_ by np.int64 to account for the types in 32-bit systems in numba.

What's Changed
* Updated to numpy prod instead of product by mborn1 in https://github.com/mborn1/pyoptex/pull/9
* Minor 'bug'fixes by RobinvdHaar in https://github.com/mborn1/pyoptex/pull/10

New Contributors
* mborn1 made their first contribution in https://github.com/mborn1/pyoptex/pull/9
* RobinvdHaar made their first contribution in https://github.com/mborn1/pyoptex/pull/10

**Full Changelog**: https://github.com/mborn1/pyoptex/compare/v1.0.0-rc1...v1.0.0-rc3

Replaced all np.product by np.prod to accomodate numpy v2

This is the first release candidate of the PyOptEx package. It includes both design of experiment, model selection and data analysis.

Reworked the package interface to make it more accessible. Added documentation.