Add missing parenthesis in docs for -author switch

Docker-DCO-1.1-Signed-off-by: Trent Ogren <tedwardo2@gmail.com> (github: misfo)

Docker-DCO-1.1-Signed-off-by: Trent Ogren <tedwardo2@gmail.com> (github: SvenDowideit)
Add the missing paren to the documentation for docker commit too

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)
Merge pull request #6686 from SvenDowideit/commit-parens-update-6310

add missing docker commit parens (update 6310)