Docs for customers to setup LogChimp on VM by proxying requests to respective Docker service

[mittalyashu]

This can be done with something like Caddy:

feedback.example.com {
    # Frontend (theme) → root
    reverse_proxy theme:3000

    # API (backend) → /api/*
    handle_path /api/* {
        reverse_proxy api:8000
    }
}