modified rugby analytics case study with increased arviz usage (#62)

* modified rugby analytics case study with increased arviz usage

* fixing precommit errors

* Resolving pre-commit-hook changes

* blackhook fix

* stimulation table fixx

* stimulation fix

* minor changes and xarray usage in simulation

* just wanted to say stimulation was a typo

* ufunc rank function for simulation

* plot fixes and more xarray usage

* cleaning comments

* missed running two cells

* final styling

* still dealing with black

* hopefully last commit

* minor plot fix

* another plot fix, my bad

* cell rerun

Author: mjhajharia