Pandas-checks

Small updates to documentation

What's Changed
* Fix typo by cparmet in https://github.com/cparmet/pandas-checks/pull/24
* Clarify purpose of package by cparmet in https://github.com/cparmet/pandas-checks/pull/25
* Add docstring to sample function by cparmet in https://github.com/cparmet/pandas-checks/pull/26


**Full Changelog**: https://github.com/cparmet/pandas-checks/compare/v0.1.6...v0.1.7

- Pandas Checks is available on PyPi and can be installed with `pip install`
- Docs are on GitHub Pages
- The `nox` test suite passes for Python 3.8-3.11, with manual testing of 3.12