When running data python script (`src/data.py`) directly through the command line,
we now use pandas to output the collected data directly as a csv to stdout.
Can then be redirected to e.g. a file to save the data in csv format.
For the first time we use the actual final extracted data from relevant studies
to do analysis on instead of just the intermediate Zotero-provided metadata.
We still inject the intermediate metadata where it may be useful (things like
citation counts and keywords) but otherwise switch to the new data.
