Define an extra_host for host-gateway

Lens0021 requested to merge lens0021/cli:host-gateway into main

(My previous post: Setting up Xdebug on Linux)

This makes it possible to use mwdev docker env set MEDIAWIKI_XDEBUG_CONFIG "client_host=host.docker.internal", which is more readable and stable(maybe?) than "client_host=172.17.0.1".

This is the solution for Linux (Fedora 36 workstation for me) and worked when I tested. But I didn't test for macOS and Windows.

Merge request reports