Update build script to generate a json formatted URL table of anything that isn't processed

[adrianco]

For any kinds of data in the content csv that don't have processors to download and prepare them for the RAG, format the data in the csv into a json table that is stored in the downloads directory so that the RAG processor can hopefully recognize and process these data sources itself.

[adrianco]

state.json file moved from authors directory to downloads directory so that it's ephemeral and excluded via .gitignore - maintains authors directory as read only while processing