feat: Configrued the `chat-backend` with a working static sharding

[demos/kafka/chat] / README.sh

#!/bin/sh
docker run --rm --sysctl net.ipv4.ip_unprivileged_port_start=0  -v $(pwd)./haproxy.cfg://usr/local/etc/haproxy/haproxy.cfg:ro haproxy:2.7 -c