Lint Stagecraft JSON

Add a **BETA** (lol, untested) script that will rewrite the page-per-thing JSON if it looks different to the dashboard. This tool is probably not good JavaScript.

It's highlighted some fairly big issues in our stub data, which I think means it's worthy of merging. Just be careful when running it, don't commit the results if they don't look decent and try and make the diff as small as possible.