Add gh-pages workflow

.github/workflows/gh-pages.yaml

@@ -0,0 +1,31 @@
+name: gh-pages
+on:
+  push:
+    branches: [v0]
+
+env:
+  NODEJS_VERSION: '16'
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          submodules: recursive
+      - name: Setup Node.js
+        uses: actions/setup-node@v2
+        with:
+          node-version: ${{ env.NODEJS_VERSION }}
+          cache: npm
+      - run: npm install
+      - name: Patch specification
+        run: npm run patch
+      - name: Include web stuff
+        run: cp -v web/* dist/
+      - name: Publish ReDoc on Github Pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./dist