Add GitHub Actions workflow to build docs

Author: hqrrr

.github/workflows/docs.yml

@@ -0,0 +1,47 @@
+name: Build docs
+
+on:
+  push:
+    branches:
+      - master
+      - main
+  workflow_dispatch:
+
+jobs:
+  build-docs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.9'
+
+      - name: Install documentation dependencies
+        run: |
+          pip install -r docs/requirements.txt
+
+      - name: Build HTML
+        working-directory: docs
+        run: |
+          make html
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs/build/html
+
+  deploy:
+    runs-on: ubuntu-latest
+    needs: build-docs
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4