Copyedit builds

Trying again since the first PR seems to have been lost.

Docker-DCO-1.1-Signed-off-by: Fred Lifton fred.lifton@docker.com (github: fredlf)
The line length here exceeds 80 chrs.
The URL (`[Automated Build](https://registry.hub.docker.com/builds/add/)`) can be pushed down into its own, for example.