Formatting fixes

Author: Alan Shaw

exercises/light_switch/problem.md

@@ -1,7 +1,7 @@
 __Write a program that acts like a light switch to turn an LED on and off.__
 
-* Attach a button to pin 5 and an LED to pin 9.
-* Use the `Button` class to detect `press` events and toggle your LED on/off.
+* Attach a button to pin 5 and an LED to pin 9
+* Use the `Button` class to detect `press` events and toggle your LED on/off
 
 ## Circuit diagram
 
@@ -22,7 +22,6 @@ Pin 5  o------------         |
                 '--|--|--'   |
                    |         |
                    ----------.---o  GND
-
 ```
 
 ## Components
@@ -35,3 +34,5 @@ Pin 5  o------------         |
 
 - Button - https://github.com/rwaldron/johnny-five/wiki/Button#usage
 - LED - https://github.com/rwaldron/johnny-five/wiki/Led#api
+
+---