Edits and fixes based on review.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
I really thought an update to this file would get rid of the word "ephemeral" as a lot of ESL people won't know the meaning unless they are somehow familiar with it, or speak Spanish or French or something, or perhaps a different one which borrowed the equivalent of this word from French like Russian.

TLDR
I find this paragraph unnecessarily complicated for it actually advices for you to do. 
Especially given that there isn't an example to elaborate on, it just complicates things.