Fix & Document all the data helper scripts

[Athanasius]

• [x] coriolis.py is erroring out
• [ ] collate.py runs on CAPI data dumps to spot new modules/ships/commodites ?
• [ ] commodity.csv from collate.py Used in: companion.py, collate.py (yes, as well as writing it).
• [ ] outfitting .csv from collate.py, used in coriolis.py
• [ ] rare_commodity.csv from ??? Used in: companion.py
• [ ] shipyard.csv from collate.py & used in it first
• [x] systems.csv from eddb.io/api. Used in eddb.py for systems.p which we no longer need.
• [ ] modules.p from coriolis.py
• [ ] ships.p from coriolis.py

[Athanasius]

The coriolis.py error turned out to be some weirdness with the coriolis-data npm install having generated coriolis-data/dist/index.json without the "symbol" keys. Removing the index.json and re-running npm install manually fixed it. So, if you see the line: assert 'symbol' in m, m in coriolis.py causing an exception:

1. cd coriolis-data
2. rm dist/index.{js,json}
3. npm install
4. Check the resultant dist/index.json has "symbol" keys in, e.g. Modules -> standard > pp <first module>

[Athanasius]

Work started in https://github.com/EDCD/EDMarketConnector/tree/issue/549-helper-scripts