JekyllData
A plugin to read '_config.yml' and data files within Jekyll theme gems
...As long as the plugin-gem has been installed properly, and is included in the Gemfile's :jekyll_plugins group, data files supported by Jekyll and present in the _data directory at the root of your theme-gem will be read. 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. ...