Add code for Pardot implementation to docs

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Fix commands to copy-paste in Mac install docs

* The commands were quite complicated. They are now much simpler to understand.
* Commands were hard to copy-paste because of parasite prompt characters. Those have been removed.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)