terraform-docs v0.10.0-rc.1 is a pre-release. It is to help gather feedback from the community as well as give users a chance to test terraform-docs in staging environments before v0.10.0 is officially released.
Action Required: This release deprecates handful of flags. Please update your workflow accordingly based on the changelog.
The official changelog will come out with the v0.10.0 release. For now, you can see the interim changelog here.