Add GitHub Actions workflow for GitHub Pages deployment

.github/workflows/ghpages.yml

@@ -0,0 +1,53 @@
+name: Docs (GitHub Pages)
+
+on:
+  push:
+    tags:
+      - "v*"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: true
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install docs toolchain
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install -r docs/requirements.txt
+
+      - name: Build docs
+        run: |
+          ./scripts/build_docs.sh
+
+      - name: Configure Pages
+        uses: actions/configure-pages@v5
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: site
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4