Minor presubmission corrections

This release involved some minor corrections to affiliations in the Supplementary Information document and improved reproducibility in the doomsday.ipynb notebook. The latter is used to download Domesday survey directly from the University of Hull website and process it for further analysis. Full scripted replication using that notebook will require a system that has certain terminal tools available for handling Microsoft Access files (see doomsday.ipynb for details), but the processed data are still included in the repo and so the primary notebook (analysis.ipynb) can be run successfully to reproduce the results and plots in the paper without having to run doomsday.ipynb.