Site crawler should have a command line option to save the results to a text file

```
WebsiteCrawler.exe  --maxsites 5 --url https://www.premierleague.com/ --output  c:\somefile.csv
```

- The option **--output** should be optional
- If the option **--output** is not specified, then existing behaviour prevails. i.e. Write the results to the console
- If specified then write the CSV to the specified file