Update cpx_red_led.py (and guidelines)

Then we have something new: a while statement. while True: essentially means, "Forever do:". while True: creates a loop. When there is a loop, the code will forever go through the code inside the loop. All code that is indented under while True: is "inside" the loop.

CircuitPython_Made_Easy_On_CPX/cpx_red_led.py

@@ -1,3 +1,4 @@
 from adafruit_circuitplayground.express import cpx
 
-cpx.red_led = True
+while True:
+    cpx.red_led = True