Allow adding forks to the comparison (i.e., show the statistics of a fork)

[primeos-work]

I just tried to compare https://github.com/jenkinsci/kubernetes-operator with another project. https://github.com/jenkinsci/kubernetes-operator is a fork of https://github.com/VirtusLab/jenkins-operator but the original project was archived as the development moved to the fork. Since there are more such cases (e.g., also if a maintainer becomes inactive and a fork gains popularity) I was wondering if this tool could allow adding forks as well. Currently this doesn't seem to be possible (I assume because it makes little sense in most cases).