More doc string formatting

Author: dastels

adafruit_turtle.py

@@ -343,11 +343,10 @@ def setheading(self, to_angle):
         directions in degrees:
 
         standard mode | logo mode
-        --------------+----------
-             0 - east | 0 - north
-           90 - north | 90 - east
-           180 - west | 180 - south
-          270 - south | 270 - west
+        0 - east | 0 - north
+        90 - north | 90 - east
+        180 - west | 180 - south
+        270 - south | 270 - west
 
         :param to_angle: the new turtle heading