add link to raywenderlich.com

Author: rayfix

README.markdown

@@ -937,7 +937,7 @@ file:
 
 ## Smiley Face
 
-Smiley faces are a very prominent style feature of the raywenderlich.com site! It is very important to have the correct smile signifying the immense amount of happiness and excitement for the coding topic. The closing square bracket `]` is used because it represents the largest smile able to be captured using ASCII art. A closing parenthesis `)` creates a half-hearted smile, and thus is not preferred.
+Smiley faces are a very prominent style feature of the [raywenderlich.com](https://www.raywenderlich.com/) site! It is very important to have the correct smile signifying the immense amount of happiness and excitement for the coding topic. The closing square bracket `]` is used because it represents the largest smile able to be captured using ASCII art. A closing parenthesis `)` creates a half-hearted smile, and thus is not preferred.
 
 **Preferred:**
 ```