This is a Jekyll version of the beautiful sb-admin provided by Startbootrap for Boostrap 4. It's been modified for Jekyll use, meaning that graphs are generated from data, and the main content (with posts) is supported.
The original site, Startbootstrap Admin 2, is developed by Blackrock Digital and the LICENSE is included here. The Jekyll version and other customizations are done by @vsoch.
In the top level directory of your forked repository run jekyll serve or bundle exec jekyll serve and browse to http://localhost:4000. If you are having trouble try rm -rf _site, followed by bundle update, then bundle exec jekyll serve.