docs: Fix typo in hello world example
explained what authConfig actually is.

Docker-DCO-1.1-Signed-off-by: Michael Neale <michael.neale@gmail.com> (github: michaelneale)
Merge pull request #4985 from drothlis/patch-1

docs: Fix typo in hello world example
Merge pull request #4984 from michaelneale/master

explained what authConfig actually is