Output JSON file with full analysis of all pages

[Mr0grog]

We currently output a set of filtered CSVs and log files to a directory. Sometimes folks want to adjust the threshold for results or filter in different ways, which means re-running the analysis and maybe changes to the code. Instead, we should output a JSON file with the complete, unfiltered analysis results alongside the CSVs. We can then easily regenerate sheets or do other transforms or filtering against that JSON data.

Bonus for a secondary command to re-generate the sheets from the JSON.