Release v1.2.0

[alancleary]

• [x] Create a branch for the release named "relase-vMAJOR.MINOR.PATCH". release-v1.2.0
• [x] Update the dependencies in the jekyll-theme-legumeinfo.gemspec file.
• [x] Update the UIkit submodule in assets/uikit/.
• [x] Do a test build using Docker Compose on your local machine using jekyll-starter-legumeinfo repo.
• [x] Bump the "version" number in jekyll-theme-legumeinfo.gemspec.
• [x] Open a PR that merges the release branch into main. PR #107
• [x] Merge the release PR after it passes testing and review.
• [x] Tag a corresponding release on GitHub.