Update 9-summary.yml

Author: Chukslord1

learn-pr/github/github-introduction-products/9-summary.yml

@@ -10,4 +10,4 @@ metadata:
   ms.topic: unit
 durationInMinutes: 1
 content: |
-  [!include[](includes/6-summary.md)]
+  [!include[](includes/9-summary.md)]