feat(workflow): add GitHub Pages deployment

This commit introduces a new GitHub Actions workflow for deploying to
GitHub Pages. The workflow is triggered on pushes to the main branch and
can also be manually dispatched. It includes steps for checking out the
repository, setting up Node.js, installing dependencies with pnpm, and
building the project. The built artifacts are then uploaded and deployed
to GitHub Pages.

.github/workflows/pages.yaml

@@ -0,0 +1,54 @@
+name: Deploy pages
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [main]
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 'lts/*'
+
+      - name: Setup @antfu/ni
+        run: npm i -g @antfu/ni
+
+      - name: Install dependencies
+        run: nci
+
+      - name: Build
+        run: nr build --base /${{github.event.repository.name}}/
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v4
+
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist
+
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    needs: build
+    runs-on: ubuntu-latest
+    name: Deploy
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4