Add github workflow to build, deploy docs

.github/workflows/docs.yml

@@ -0,0 +1,29 @@
+name: docs
+on:
+  push:
+    branches:
+      - master
+jobs:
+  docs:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Check out source
+        uses: actions/checkout@v3
+
+      - name: Install Sphinx dependencies
+        run: |
+          pip install -r ./docs/requirements.txt
+
+      - name: Build HTML
+        run: |
+          cd docs/
+          make html
+
+      - name: Deploy HTML to GitHub Pages
+        uses: peaceiris/[email protected]
+        with:
+          publish_branch: gh-pages
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./docs/build/html