Add deploy-docs workflow for Sphinx -> GitHub Pages deployment

.github/workflows/deploy-docs.yml

@@ -0,0 +1,38 @@
+name: Deploy docs
+
+on:
+  push:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Build docs
+        run: |
+          cd docs
+          pip install -r requirements.txt
+          make html
+      - name: Upload docs artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs/build/html
+  deploy:
+    runs-on: ubuntu-latest
+    needs: build
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    permissions:
+      pages: write
+      id-token: write
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4