Note: in the actual analysis, the effect of December Tiers was
removed.

CHANGES:

1. Implemented log-linear model for weekday effect in I->R hazard;
2. Updated summary.py and within_between.py to match;
3. Implemented linear random walk for new gamma0 parameter.
4. Implemented per-parameter data structure in output HDF5 file.

All project config now goes in `pyproject.toml`.