Document all extrudes gear ratios

[ChaosBlades]

Building a Voron v0.0 and was extruding way to much extra filament to be a simple rotation_distance inaccuracy. Turns out I had the wrong gear ratio in the config. (50:10 instead of 50:17) I searched the github and website and could not find where the gear ratios were. Seems they are not documented, at least not very well. Only solution was to ask on the discord.

[bdbell]

That's actually a really good idea. Let me see what we can do.