Carefree-pyo3

Release Note

> I'm pretty satisfied with this version so I emphasize it with a `Release Note` title!

- Refactored the code base into workspaces.
- CI will now publish the rust core (`cfpyo3_rs_core`) to crates.io.

**Full Changelog**: https://github.com/carefree0910/carefree-pyo3/compare/v0.1.7...v0.1.8

This version integrated dependencies into `pyproject.toml` (c5a383605d907a8ace928068df0e60817dcc6827), now installing `carefree-pyo3` becomes much easier.

Implemented several array ops which are frequently used.

Also integrated some of them to the `DataFrame` class.

**Full Changelog**: https://github.com/carefree0910/carefree-pyo3/compare/v0.1.5...v0.1.6

First usable version (i.e., multi-platform, multi-python support).

Initial public release, mainly to make sure that the project is scaffolded correctly, so workflows can work as expected.