Grammar and punctuation fixes

Docker-DCO-1.1-Signed-off-by: John Gardiner Myers <jgmyers@proofpoint.com> (github: johngmyers)
Wording improvements

Docker-DCO-1.1-Signed-off-by: John Gardiner Myers <jgmyers@proofpoint.com> (github: johngmyers)
Merge pull request #3716 from johngmyers/patch-1

Grammar fixes and wording improvements