Future selection and transformation steps may be complex and require multiple parameters. Even some current steps require two parameters (such as the range transformation steps) or may benefit from multiple parameters (like the "match" transformation step, which may benefit from a "regex" boolean parameter). However, using commas to separate parameters may not be appropriate in most cases.

Consider making the "config" property of translation steps either an array of configuration values, or a configuration object.

Also this way translation step classes may know (and tell Web2Cit-Editor) the names of the parameters, to better guide users.