Spreadsheet config for packagers

[Mandera]

Would be nice to have an editable spreadsheet instead of going into every single metadata.json.

I will need an environment-wide config #70, what if that was the only config?

Would be pretty interesting actually. Then every repo is "normal" when cloned / forked. The metadata.json config is only relevant when they are all together

• Workflow would still have that simple entry point
• generate.py would be out of place though, as well as the git hook, hmm