Add nginx to docker-compose and customize client_max_body_size

Configure the nginx client_max_body_size in the Dockerfile or docker-compose.yml file in order to make sure we no longer run into issues of deployments with maximum request sizes of 1 MB. Set the value to 2GB.

Whether it is possible to configure this setting in Docker, specifying and checking this setting should be added as a server setup step in README.md

Currently, the docker-compose configuration doesn't have Nginx in front of the Story telling tool. Nginx should be added in a 3-tier app deployment configuration to better mimick what is deployed in production.