Improvements to Documentation:

* FormatItems() in CSV now reflects over all the item fields to make the CSV row, this gives it the same functionality as the JSON equiv
* Both JSON/CSV item interfaces now start from -48 instead of 0, that's what the Terraria IDs start from
* CSV interface now adds every field in quotes, to avoid unintentional non-escaping of fields.

(Not sure why the diff wants to change the whole file, most of it is unchanged, just pay attention to FormatItems() in CSVFormatter.cs)