Update ports section in services.md

[chubi-x]

Explicitly state the dangers if a port mapping binds to all interfaces

Description

We recently discovered that docker was bypassing our firewall rules when forwarding ports from a container using the standard <host port>:<container port> syntax. What this meant was that the container was effectively visible to the entire internet. It was only after some digging did we discover that it is possible and even recommended to explicitly bind the host port to localhost so it doesn't accept connections from everywhere. This PR updates the docs to explicitly state the potential dangers of not specifying a localhost when exposing docker container ports.

Reviews

• [ ] Technical review
• [ ] Editorial review
• [ ] Product review