ExperimentalDesignGeneratorandRandomiser - 'EDGAR': Experimental Design Generator and Randomiser

Native R implementation of 'EDGAR', the Experimental Design Generator and Randomiser. 'EDGAR' was originally developed as a suite of 'Excel' <https://www.microsoft.com/microsoft-365/excel> workbooks by the Biometrics team at Rothamsted Research <http://www.edgarweb.org.uk/>. The algorithms were subsequently re-implemented in the open-source 'Python' <https://www.python.org/> project 'rotsl/edgar' <https://rotsl.github.io/edgar/>, distributed as the 'edgar-design' package on 'PyPI' <https://pypi.org/project/edgar-design/>. This R package is a native R port of that 'Python' implementation: it does not require 'Python', 'reticulate' <https://CRAN.R-project.org/package=reticulate>, or any external service at runtime, and provides deterministic, reproducible randomisation for nine experimental designs including alpha designs (Patterson and Williams, 1976) <doi:10.1093/biomet/63.1.83>. Cross-language reproducibility with the 'Python' implementation is achieved by porting the Mersenne Twister seeding implementation from 'CPython' <https://github.com/python/cpython> and the Fisher-Yates shuffle to native R.