Update main.yml

Author: emmaco

.github/workflows/main.yml

@@ -9,3 +9,7 @@ jobs:
     steps:
       - name: Greet the User
         run: echo "Hello World!"
+        # List all files in the current directory for comparison before and after actions/checkout@v2.
+      - run: ls -l
+      - uses: actions/checkout@v3
+      - run: ls -l