Initial copy edits to builds.md

Revised to match new UI, fixed links, copy edits and improvements.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

More revisions to builds.md

Corrections to automated build process, copy edits.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

Edits based on Sonat's feedback

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
Merge pull request #6826 from fredlf/copyedit-builds

Copyedit builds