Fork the repo and make changes on your fork in a feature branch:
- If it's a bugfix branch, name it XXX-something where XXX is the number of the issue
- If it's a feature branch, create an enhancement issue to announce your intentions, and name it XXX-something where XXX is the number of the issue.
Docker maintainers use LGTM (looks good to me) in comments on the code review to indicate acceptance.
A change requires LGTMs from at least one maintainer.