Docs styling update/upgrade

Closes https://github.com/dotcloud/docker/issues/6514
Closes https://github.com/dotcloud/docker/issues/6377
Closes https://github.com/dotcloud/docker/issues/6514
Closes https://github.com/dotcloud/docker/pull/6502

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Merge pull request #6517 from ostezer/docs-styles-update

Docs styles update