add a secrets example
add a secrets example

Shopify/shipit-engine,ershad/shipit-engine,Shopify/shipit-engine,ershad/shipit-engine,Shopify/shipit-engine,perobertson/shipit-engine,perobertson/shipit-engine,perobertson/shipit-engine,ershad/shipit-engine,Shopify/shipit-engine,perobertson/shipit-engine,ershad/shipit-engine,Shopify/shipit-engine,ershad/shipit-engine,perobertson/shipit-engine