docs: add sphinx documentation

Author: gpmp-dev

.github/workflows/docs.yml

@@ -0,0 +1,59 @@
+name: Publish documentation
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install package and documentation dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install -e ".[docs]"
+
+      - name: Build documentation
+        env:
+          GPMP_LOG_LEVEL: WARNING
+          MPLCONFIGDIR: /tmp/matplotlib-cache
+        run: sphinx-build -M html docs/source docs/build -E
+
+      - name: Configure GitHub Pages
+        uses: actions/configure-pages@v5
+
+      - name: Upload documentation artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs/build/html
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4