Update docs for macOS hostname (#5805)
Update docs for macOS hostname (#5805)

See: https://github.com/docker/docker.github.io/blob/master/docker-for-mac/release-notes.md#docker-community-edition-17120-ce-mac46-2018-01-09-stable
anweiss/docker.github.io,JimGalasyn/docker.github.io,johnstep/docker.github.io,johnstep/docker.github.io,thaJeztah/docker.github.io,JimGalasyn/docker.github.io,johnstep/docker.github.io,thaJeztah/docker.github.io,londoncalling/docker.github.io,anweiss/docker.github.io,JimGalasyn/docker.github.io,JimGalasyn/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io,anweiss/docker.github.io,londoncalling/docker.github.io,londoncalling/docker.github.io,anweiss/docker.github.io,docker/docker.github.io,johnstep/docker.github.io,docker/docker.github.io,docker/docker.github.io,johnstep/docker.github.io,JimGalasyn/docker.github.io,anweiss/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io