add workflow for documentations

.github/workflows/docs.yaml

@@ -0,0 +1,31 @@
+name: documentation
+
+on:
+  push:
+    branches:
+      - docs
+
+jobs:
+  docs:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
+      - name: Install dependencies
+        run: |
+          pip install sphinx sphinx_rtd_theme myst_parser
+      - name: Generate the docs
+        run: |
+          cd docs
+          make generate-docs
+      - name: Deploy to GitHub Pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          publish_branch: gh-pages
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: build
+          force_orphan: true