ci: added basic docs build & publish workflow

.github/workflows/docs.yml

@@ -0,0 +1,59 @@
+name: Docs
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Setup Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade poetry
+          poetry install
+
+      - name: Build docs
+        run: make docs
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: documentation
+          path: ./docs/_build
+
+  deploy:
+    name: deploy
+    runs-on: ubuntu-latest
+    needs: [build]
+    if: github.ref == 'refs/heads/master'
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Download artifact
+        uses: actions/download-artifact@v2
+        with:
+          name: documentation
+          path: ./docs/_build
+
+      - name: Deploy to GitHub Pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          publish_dir: ./docs/_build
+          publish_branch: gh-pages
+          destination_dir: docs