Add a (Production - Consumption) Graph

[miketwo]

I assume this has been suggested before, but I honestly couldn't find it when I searched.

The Production and Consumption graphs are great, but often I'm mentally taking the difference between the two. I would love a 3rd graph that shows the difference, so I can focus on items that are being used more than being produced.

[Factory Lobster]

Refer to this thread: https://www.reddit.com/r/factorio/comme ... ent_power/