Fix HTTP port, move unneccesary sed and blank lines

The main reason for changing the disk size to 30Gigs is to save from having to go look on Docker's website to deviate from the default.

The SSH_PORT right after the external_url looked like a mistake.

Using port 8080 at the end of the external_url did end up breaking the container for me so I changed it to 8888

external_url seemsto configure Nginx to listen on the specified port, so when publishing it with docker, it needs to be the external and internal port of the container.

Everything worked on my side without sed, but I really like the KungFu move you did with that, so I would like to still have it on the page.