nixos/cloudflare-ddns: fix module description

      description = ''

        Path to a file containing the Cloudflare API authentication token.

        The file content should be in the format `CLOUDFLARE_API_TOKEN=YOUR_SECRET_TOKEN`.

        The service user `${cfg.user}` needs read access to this file.

        The service user needs read access to this file.

        Ensure permissions are secure (e.g., `0400` or `0440`) and ownership is appropriate

        (e.g., `owner = root`, `group = ${cfg.group}`).

        Using `CLOUDFLARE_API_TOKEN` is preferred over the deprecated `CF_API_TOKEN`.

      '';

      example = "/run/secrets/cloudflare-ddns-token";