Make note about incorrect stepper silkscreen on Stealthburner Toolhead PCB

[gsokoll]

I have a rev 2 Stealthburner 2-piece PCB, and recently installed it as part of Stealthburner upgrade on my Voron. The extruder stepper didn't work when powered up. I suspected an issue with the stepper connections, and checked but it all seemed correct.

But now I notice that this is a known issue (https://github.com/hartk1213/MISC/issues/29) which has been closed. There is a note in the readme that the rev 4 PCB "stepper wiring has now been fixed", but no indication what the issue was or what was wrong with previous rev's.

Any chance the readme could be updated with a more prominent note to the issue with older rev PCB's ?