ci: add GitHub Pages deployment workflow

.github/workflows/deploy-website.yml

@@ -0,0 +1,42 @@
+name: Deploy Website
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'index.html'
+      - '.github/workflows/deploy-website.yml'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+
+      - name: Prepare site
+        run: mkdir _site && cp index.html _site/
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v4
+        with:
+          path: _site
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4