Decided to extend the `python-calculator` to work with the [Git
Collaboration](https://github.com/ns-rse/git-collaboration) course that is being developed.

+ Consolidate functions to `arithmetic` module
+ Add typehints and numpy doc strings to functions
+ Remove exisiting issue templates
+ Add zero division issue template
+ Add square root issue template
+ Switch to `pyproject.toml` for package configuration
+ `pylint` configuration file
+ Add [pre-commit](https://pre-commit.com) hooks...
  + `black`
  + `codespell`
  + `ruff`
  + `markdownlint-cli2`
  + `mypy`
  + `numpydoc`
  + `prettier`
  + `pylint` (local)
  + `pyupgrade`
+ Parametrise the tests

Includes tweak to test workflow.