Added Learn Guide link

Author: Melissa LeBlanc-Williams

docs/index.rst

@@ -23,9 +23,11 @@ Table of Contents
 .. toctree::
     :caption: Tutorials
 
+    RA8875 Touch Display Driver Board Learn Guide <https://learn.adafruit.com/ra8875-touch-display-driver-board>
+
 .. toctree::
     :caption: Related Products
-    
+
     RA8875 Driver Board for 40-pin TFT Touch Displays - 800x480 <https://www.adafruit.com/product/1590>
 
 .. toctree::