JekyllData
A plugin to read '_config.yml' and data files within Jekyll theme gems
...Their contents will be added to the site's internal data hash, provided, an identical data hash doesn't already exist at the site-source. If the theme-gem also includes a _config.yml at its root, then it will be read as well. The resulting config hash will be mixed into the site's existing config hash, filling in where the keys are not already defined. In other words, the config file at source will override corresponding identical keys in a _config.yml within the theme-gem.