Build website automatically and publish to gh-pages

.github/workflows/pages.yml

@@ -0,0 +1,26 @@
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  docs:
+    name: Build documentation
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+    - name: Set up Python
+      uses: actions/setup-python@v1
+    - name: Install dependencies
+      run: |
+        python3 -m pip install --upgrade pip
+        pip install -r doc/requirements.txt
+    - name: Build sphinx documentation
+      run: |
+        make -C doc html
+    - name: Deploy to gh-pages
+      uses: JamesIves/github-pages-deploy-action@4.1.1
+      with:
+        branch: gh-pages # The branch the action should deploy to.
+        folder: doc/_build/html # The folder the action should deploy.