feat: Add GitHub Actions workflow for Helm chart automation

Author: DrumRobot

.github/workflows/pages.yaml

@@ -0,0 +1,34 @@
+name: Release Helm Chart
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - '.github/workflows/pages.yaml'
+      - 'charts/**'
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Set up Helm
+        uses: azure/setup-helm@v3
+        with:
+          version: v3.13.3
+
+      - name: Create Helm index
+        run: |
+          mkdir -p ./gh-pages
+          helm package charts/* --destination ./gh-pages
+          helm repo index ./gh-pages --url https://es6kr.github.io/nginx-cert-issuers
+
+      - name: Deploy to GitHub Pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./gh-pages
+          publish_branch: gh-pages