Update snake.yml

.github/workflows/snake.yml

@@ -2,7 +2,7 @@ name: Generate snake animation
 
 on:
   schedule: # execute every 12 hours
-    - cron: "* */12 * * *"
+    - cron: '0 */12 * * *'
 
   workflow_dispatch:
 
@@ -18,13 +18,15 @@ jobs:
     timeout-minutes: 5
 
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
       - name: generate snake.svg
         uses: Platane/snk/svg-only@v3
         with:
           github_user_name: ${{ github.repository_owner }}
           outputs: dist/snake.svg?palette=github-dark
 
-
       - name: push snake.svg to the output branch
         uses: crazy-max/ghaction-github-pages@v3.1.0
         with: