Add QA instructions

Author: oxplot

board/Readme.md

@@ -6,3 +6,12 @@ ready for manufacturing and they include part numbers as well.
 ![fpx pcb front side](./pcb-front.png) ![fpx pcb back side](./pcb-back.png)
 
 ![open source hardware mark](./oshw.svg) fpx is certified open source hardware
+
+## QA
+
+1. Program the board with Atmel Studio. Ensure erase, flash and verify
+   all show "OK".
+2. Configure the board with [fpx web
+   configurer](https://fpx.oxplot.com/#configure). Ensure the green
+   light flashes.
+3. Measure the output terminals. It should be 5 volts.