ci: set up automated github pages deployment workflow

.github/workflows/docs.yaml

@@ -0,0 +1,47 @@
+name: Deploy to GitHub Pages
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - 'website/**'
+  workflow_dispatch:
+
+concurrency:
+  group: github-pages-deployment
+  cancel-in-progress: false
+
+permissions:
+  contents: write
+
+jobs:
+  deploy:
+    name: Deploy to GitHub Pages
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: 'npm'
+          cache-dependency-path: website/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+        working-directory: website
+
+      - name: Build Docusaurus
+        run: npm run build
+        working-directory: website
+
+      - name: Deploy to gh-pages
+        uses: peaceiris/actions-gh-pages@v4
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./website/build
+          publish_branch: gh-pages
+          commit_message: "docs: update GitHub Pages [skip ci]"