feat: conversion utility from raster (BIEN ranges) to .RDS

@benscarlson please complete with mini-spec of parameters

List of inputs (e.g. file name, parameters with types/ranges). Should this utility run over 1 file at a time, an explicit list of files, or all files in a directory?
Output specification such as file format, dimensions (eg fields or columns)
Pointer to reference code, if available
Pointer to test data