New option to download CSV from remote source, and convert to .xlsx on the fly

curl can download remote files easily. It would be nice to string this together with the rest of the automation, so the user isn't required to have the file stored locally already.

```bash
curl -O https://your-remote/server/file.csv
```

Potential new flag could work like this.

```bash
main.py --remote [url.csv] ...rest of options
```

