- added `noxfile.py` to automate linting, testing, coverage, and doc building
- moved `requirements/core.txt` to `requirements.txt`
- update optional-dependencies within `pyproject.toml` to decompose dev dependency group
- added `compile_readme_and_arrange_docs.py` to sphinx `Makefile`
- added pypandoc as dependency to make pandoc python package installable
- edited `compile_readme_and_arrange_docs.py` and `sphinx/Makefile` to use pypandoc
- added `docs/pandoc` where pypandoc install pandoc to `.gitignore`
- added pandoc pathing variables to `sphinx/conf.py`

- Updated Issue and PR templates
- Updated `CONTRIBUTING.md` to latest recommended usage
- Linting changes
- Added `.coveragerc` to configure coverage report
- Added `pytest` options to `pyproject.toml`
- Added filter warnings to pytest options.
- Modified `tabulation.py` for `DeprecationWarning` with use of `.drop()`
- Future TODO: add version bump nox session
- Future TODO: use nox in GH actions?
- Future TODO: increase coverage to 95%+.
    - Update `CONTRIBUTING.MD`, `PULL_REQUEST_TEMPLATE.md` ,and `.coveragerc` to reflect this requirement.

- removed `MIN_COVERAGE_PERC` within `noxfile.py`