Update manage-repository-events.md
Update manage-repository-events.md

- Update activity stream
- Update event permissions
londoncalling/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,docker/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io