update indexer configuration a bit

.github/workflows/release.yml

@@ -157,7 +157,7 @@ jobs:
             ./helm-charts/index.yaml \
             ./helm-charts
       - uses: yKicchan/generate-directory-listing-action@v1
-        with: {target: ., override: true}
+        with: {target: ., ignore: "**/index.html", override: true}
       - name: Commit and push the changes
         run: |
           git config user.name "${{ github.actor }}"