Add Github action

.github/workflows/gh-pages.yml

+name: Github Pages CI
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    name: Build Documentation
+    # Specify runner + deployment step
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          submodules: "true"
+
+      - name: Install Doxygen
+        run: sudo apt-get install doxygen graphviz git -y
+        shell: bash
+
+      - name: Generate Doxygen Documentation
+        run: doxygen Doxyfile
+        shell: bash
+
+      - name: Create .nojekyll (ensures pages with underscores work on gh pages)
+        run: touch docs/html/.nojekyll
+        shell: bash
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs/html
+
+  deploy:
+    name: Deploy to GitHub Pages
+    # Add a dependency to the build job
+    needs: build
+
+    # Grant GITHUB_TOKEN the permissions required to make a Pages deployment
+    permissions:
+      pages: write # to deploy to Pages
+      id-token: write # to verify the deployment originates from an appropriate source
+
+    # Deploy to the github-pages environment
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4 # or specific "vX.X.X" version tag for this action