I changed the "JSON maker" I used to convert CProjects to JSON last week to be useful for a more general use case, being more user-friendly and having more options, like grouping by species and minifying. It's now called ctj (CProject to JSON), although that name may be changed to something more clear or appropriate. The GitHub repository can be found here.
CProjects are the output of the ContentMine tools. The output is a directory of directories with XML files, JSON files, and a directory with more XML files, some of which may be empty. ctj converts all this into one JSON file, or several, if you want. Here is a guide on how to use it.