Add link to CPY Essentials Learn guide for board module

Author: tekktrik

shared-bindings/board/__init__.c

@@ -43,10 +43,14 @@
 //| Common container for board base pin names. These will vary from board to
 //| board so don't expect portability when using this module.
 //|
-//| The most common use of this module is to use serial communciation buses with
+//| Another common use of this module is to use serial communciation buses with
 //| the default pins and settings.  For more information about serial communcication
 //| in CircuitPython, see the :mod:`busio`.
 //|
+//| For more information regarding the typical usage of `board`, refer to the CircuitPython
+//| Essentials Learn guide:
+//| https://learn.adafruit.com/circuitpython-essentials/circuitpython-pins-and-modules
+//|
 //| .. warning:: The board module varies by board. The APIs documented here may or may not be
 //|              available on a specific board."""