Update _index.md

Signed-off-by: Lee Calcote <[email protected]>

Author: leecalcote

content/_index.md

@@ -9,7 +9,7 @@ title: Academy
 
 [Learning Paths](https://cloud.layer5.io/academy/learning-paths)  
 
-[Challenge](https://cloud.layer5.io/academy/challenges)  
+[Challenges](https://cloud.layer5.io/academy/challenges)  
 
 
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