Single tank (#891)

* add note about dual blocks

* fix simulator to match hardware

* updated wording

docs/reference/motors/synced/steer.md

@@ -39,6 +39,13 @@ motors.largeBC.steer(-15, -75)
 
 ## ~
 
+## ~ hint
+
+Only one set of synchronized motors will run at the same time. Once you launch tank/steer, it will cancel any existing synchronized speed command.
+
+## ~
+
+
 ## Examples
 
 ### Make a slight right

docs/reference/motors/synced/tank.md

@@ -35,6 +35,12 @@ motors.largeBC.tank(-75, -75)
 
 ## ~
 
+## ~ hint
+
+Only one set of synchronized motors will run at the same time. Once you launch tank/steer, it will cancel any existing synchronized speed command.
+
+## ~
+
 ## Examples
 
 ### Tank forward and backward