bug/monorepo: turbo-nextjs does NOT deploy if I follow the REAME

[drago1520]

The README was misleading, as if I could deploy multiple apps with 1 deploy by exposing all ports.
Instead, to deploy the turborepo monorepo, I needed to:

1. NIXPACKS_TURBO_APP_NAME = "web" (or docs) based on `package.json.name"
2. expose only port 3001