Improve documentation workflow (#163)

* Compact project relative paths from doc directory

* Remove committed example_list.md

- generate example_list from cmake for documentation

* Fix doxygen same-line comments

* Add workflow for generating documentation

.github/workflows/documentation.yaml

@@ -0,0 +1,34 @@
+name: Documentation
+
+# Triggers the workflow on push events only for the master branch
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+  build-documentation:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Install Doxygen
+      run: |
+        sudo apt-get update
+        sudo apt-get install doxygen
+
+    - name: Build HTML documentation
+      run: |
+        cmake -S . -B build
+        cmake --build build --target doc
+
+    # Deploy the HTML documentation to GitHub Pages
+    - name: GH Pages Deployment
+      uses: peaceiris/actions-gh-pages@v3
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        publish_dir: build/doc/doxygen/html/
+        enable_jekyll: false
+        allow_empty_commit: false
+        force_orphan: true
+        publish_branch: gh-pages