Include doc generation in github workflows

.github/workflows/documentation.yml

@@ -0,0 +1,46 @@
+name: Documentation generation & update
+
+on:
+  push:
+    tags:
+      - '*'
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  generate:
+    name: Generate the documentation
+    runs-on: ubuntu-latest
+    steps:
+      - name: Clone
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Install APT dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install graphviz doxygen
+      - name: Generate the documentation
+        run: make doc
+      - name: Upload documentation bundle
+        uses: actions/upload-artifact@v4
+        with:
+          name: documentation
+          path: build/doc/html/
+
+  deploy:
+    name: Deploy the documentation on Github pages
+    runs-on: ubuntu-latest
+    needs: generate
+    if: github.event_name == 'push'  && (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/'))
+    steps:
+      - name: Download documentation bundle
+        uses: actions/download-artifact@v4
+      - name: Deploy documentation on pages
+        uses: peaceiris/actions-gh-pages@v4
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: documentation/