[Docs] Added information on soldering diodes in parallel (#13117)

Co-authored-by: Ryan <fauxpark@gmail.com>

docs/hand_wire.md

@@ -113,7 +113,7 @@ Don't hold the iron on the solder/joint longer than necessary. Heat will be cond
 
 #### Soldering the Diodes
 
-Starting at the top-left switch, place the diode (with tweezers if you have them) on the switch so that the diode itself is vertically aligned, and the black line is facing toward you. The input lead of the diode should be touching the left contact on the switch, and the bent, output end should be facing to the right and resting on the switch there, like this:
+Starting at the top-left switch, place the diode (with tweezers if you have them) on the switch so that the diode itself is vertically aligned, and the black line is facing toward you. Make sure the diodes are soldered in parallel (diode outputs shouldn't connect to diode inputs). The input lead of the diode should be touching the left contact on the switch, and the bent, output end should be facing to the right and resting on the switch there, like this:
 
 ![soldering-diodes-01.png](https://raw.githubusercontent.com/noroadsleft/qmk_images/master/docs/hand_wire/soldering-diodes-01.png)