docs: Add GitHub workflow.

.github/workflows/deploy.yml

@@ -0,0 +1,48 @@
+name: Deploy
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+
+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
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20.x"
+          cache: "npm"
+
+      - name: Install Node dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run docs:build
+
+      - uses: actions/configure-pages@v5
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs/.vitepress/dist
+      - name: Deploy
+        id: deployment
+        uses: actions/deploy-pages@v4