The page build failed for the `master` branch with the following error

[mgifford]

I got this error from Jekyll when pushing this to Github:

The page build failed for the master branch with the following error:

The submodule registered for ./elementary could not be cloned. Make sure it's using https:// and that it's a public repo. For more information, see help.github.com/en/github/working-with-github-pages/troubleshooting-jekyll-build-errors-for-github-pages-sites#invalid-submodule.

I assume this is because "http://rubygems.org" is used rather than source "https://rubygems.org".