Correct example of export command usage in documentation
Correct example of export command usage in documentation

The documentation was showing the old style command invocation
from when the review notes export was done with a server program.

Change the example to show usage via the plugin's ssh command.

Change-Id: Iecdb73d9e6b331960a5c9ae8017a22694e912e11

GerritCodeReview/plugins_reviewnotes