Document private 7DTD Telnet binding for IW4MAdmin

[CoreyUK]

Summary

• Add a configurable private bind for the 7DTD Telnet port in the Compose example.
• Document using a stable private host address instead of a Docker container IP.
• Add the native 7DTD parser and log name to the IW4MAdmin reference.

Why

Docker container addresses can change whenever a server is recreated. Publishing Telnet on a stable private host address follows the existing IW4MAdmin connection model used by the other games while keeping port 8081 off public interfaces. The example defaults to loopback for host-side tools.