default configuration not distributed with the gem

[afeld]

Background Information

@tbaxter-18f and I noticed that the _config.yml values weren't being inherited from the released version(s) of the gem. Turns out that when you specify path: in the Gemfile, it picks up all those local files, but when released, it's only including the files and folders here:

https://github.com/18F/uswds-jekyll/blob/e93b9ab574da4345d7105ad392c5e311584d2fef/uswds-jekyll.gemspec#L13

Implementation Steps

• [ ]

Acceptance Criteria

• [ ] Configuration inherited by sites using the theme as a released gem

[adborden]

To elaborate, theme config inheritance was added in Jekyll 4.0.