Refresh log debugging docs

This documents how to gzip all the logs before sending a support request
and how to tail all of the ER's web workers.

One could also use `docker exec -t -i CONTAINER /bin/bash` and you don't even need to be on the host machine to tail the logs. It's only really useful when using boot2docker, though.
If you don't, it basically becomes the same number of lines as the manual one. It's not piping it as root, which would be pure evil. But yeah, totally up for debate.