Update primer/css to the latest version. With that update, support for light/dark color modes was added.
The latest version of primer/css doesn't work with sassc, so we need to use Dart sass, which is what sass-embedded uses. In order to use sass-embedded we need jekyll-sass-converter>=2.0 which is only supported in jekyll>=4.0. So, this also increases the minimum jekyll version to 4.0.
Also bumps this project's version to prepare for a release.
Update
primer/cssto the latest version. With that update, support for light/dark color modes was added.The latest version of
primer/cssdoesn't work withsassc, so we need to use Dart sass, which is whatsass-embeddeduses. In order to usesass-embeddedwe needjekyll-sass-converter>=2.0which is only supported injekyll>=4.0. So, this also increases the minimumjekyllversion to4.0.Also bumps this project's version to prepare for a release.