move git commit and push after checking for diff

.github/workflows/docs.yaml

@@ -27,9 +27,9 @@ jobs:
           git config user.name 'GitHub Action'
           git config user.email 'action@github.com'
           git add .
-          git commit -m "Aotumated: Update starship documentation from starship repo"
           if git diff --cached --quiet; then
               echo "No changes to commit."
           else
+              git commit -m "Aotumated: Update starship documentation from starship repo"
               git push
           fi