ci: add gh pages deployment

.github/actions/pages.yml

@@ -0,0 +1,23 @@
+name: GitHub Pages
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    concurrency:
+      group: ${{ github.workflow }}-${{ github.ref }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v4
+        if: github.ref == 'refs/heads/main'
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./public