DataDict needs to be exposed and editable

[mrfnord]

The DataDict object is buried in DataDict_setup() and passed around by functions. It is not inclusive of all reports, and including all ERCOT reports would make the object overwhelming, but allowing users to add new items to the DataDict would make the scraper more broadly useful.

All ERCOT HTML reports:
https://mis.ercot.com/misapp/servlets/ReportExplorer?reportTypeId=rptexp&reportSourceType=List