Added Kattni's suggestion

Author: Melissa LeBlanc-Williams

adafruit_featherwing/gps_featherwing.py

@@ -62,7 +62,7 @@ def __init__(self, update_period=1000, baudrate=9600):
 
     def update(self):
         """
-        Make sure to call gps.update() every loop iteration and at least twice
+        Make sure to call ``gps.update()`` every loop iteration and at least twice
         as fast as data comes from the GPS unit (usually every second).
 
         :return: Whether it has parsed new data