Formatting fixes

Author: Alan Shaw

exercises/spin_motor_spin/problem.md

@@ -1,8 +1,8 @@
 __Attach a motor to pin 9 and start it spinning!__
 
-* Use `board.wait` to stop the motor spinning after 2 seconds.
-* Start it spinning again after another second.
-* Ensure this loop repeats infinitely.
+* Use `board.wait` to stop the motor spinning after **2 seconds**
+* Start it spinning again after another second
+* Ensure this loop repeats infinitely
 
 Hint: You could use the motor `start` and `stop` events to stop/start the motor.
 
@@ -37,3 +37,5 @@ Pin 9  o---/\/\/---|  Transistor
 
 - Board - https://github.com/rwaldron/johnny-five/wiki/Board#api
 - Motor - https://github.com/rwaldron/johnny-five/wiki/Motor#api
+
+---