Project specific runners that forks automatically inherit from parent project
Description
In GitLab there exists specific runners for a specific project, shared runners that can be used by all projects, or group runners.
For a community using forks as part of the work-model there is a need for project-specific runners. So that forks automatically inherit the runners that the parent project has set up. Since the .gitlab-ci.yml file is inherited by the forks, so should the runners, as the gitlab-ci.yml specifies what runners to use.
Proposal
Add project-specific runners that project owner can create, and that is automatically shared and enabled in the forks.