Add HOWTO get ECS-related log

[khashf]

Document on how to get all ECS-related log from an ECS instance hosted on EC2 instance.
Here is how it looks: https://github.com/khashf/hackoregon-aws-infrastructure/blob/howto-get-logs/docs/HOWTO-get-ecs-logs.md

[iant01]

The output from docker inspect and docker info may be useful to gather at the same time as the logs and add them to the archive file (zip). An alternative would be to install the collection script and have a cron job the periodically runs it (removing and replacing the archive file so that there is only ever one, not a never endig list) and add the file to the cloudwatch logs config file so that it collects them for us. This might be useful during development and disabled once in production.