Add docs-only workflow

.github/workflows/gh-pages.yml

@@ -0,0 +1,34 @@
+name: Deploy to GitHub Pages
+
+on:
+  workflow_dispatch:
+    inputs:
+      branch:
+        type: choice
+        description: Which branch to deploy?
+        required: true
+        options:
+          - main
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.inputs.branch }}
+      - name: Enable pnpm
+        run: "corepack enable"
+      - name: Use Node.js 22.x
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22.x
+          cache: pnpm
+      - run: pnpm install
+      - run: npm run build
+      - run: npm run docs
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v4
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: docs