Add Minimal Mistakes skin configuration to Jekyll cookiecutter #31
Description
Background
It would be useful for users to be able to pass what Minimal Mistakes skin they want prebuilt in the greening.yaml for some additional customization
Relevant context
- Minimal Mistakes available skins is here
- Add to the GreeningConfig DEFAULT_YAML here
- Update the _config.yml configuration here
Action
Add minimal_mistakes_skin to greening.yaml with dark as the default and a comment that directs users to the available skins. Update the _config.yml in the Jekyll cookiecutter to incorporate this