Add a little info on how to talk to the TLS encrypted Docker Socket

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)
Merge pull request #8583 from SvenDowideit/minimal-curl-command-to-tls-docker-socket

Add a little info on how to talk to the TLS encrypted Docker Socket