ci: add github pages doxygen job

Signed-off-by: Alexander Linne <[email protected]>

.github/workflows/build.yaml

@@ -8,6 +8,8 @@ on:
       - "[0-9]+.[0-9]+.[0-9]+"
   pull_request:
     types: [opened, reopened, synchronize]
+  merge_group:
+    types: [checks_requested]
 
 jobs:
   formatting:
@@ -55,8 +57,51 @@ jobs:
           dotnet-version: 8.0.303
       - name: Run tests
         run: dotnet test -c Debug
-  deploy:
-    name: Deploy
+  publish-docs:
+    name: Publish documentation
+    runs-on: ubuntu-latest
+    needs:
+      - formatting
+      - coverage
+      - run-tests
+    steps:
+      - name: Checkout
+        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+      - name: Setup doxygen
+        run: sudo apt-get install doxygen
+      - name: Create temporary directory
+        run: |
+          tmpdir=$(mktemp -d -p "$RUNNER_TEMP")
+          mkdir -p $tmpdir
+          relative_path=$(realpath --relative-to="$GITHUB_WORKSPACE" "$tmpdir")
+          echo "Created temporary directory $tmpdir ($relative_path relative to $GITHUB_WORKSPACE)"
+          echo "DOCS_TEMP_DIR=$relative_path" >> "$GITHUB_ENV"
+      - name: Checkout gh-pages branch
+        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with:
+          ref: gh-pages
+          path: ${{ env.DOCS_TEMP_DIR }}
+      - name: Generate documentation
+        working-directory: ${{ env.DOCS_TEMP_DIR }}
+        run: |
+          find . -mindepth 1 -not -path './.git*' -delete
+          doxygen "$GITHUB_WORKSPACE/documentation/Doxyfile"
+          touch .nojekyll
+      - name: Commit and push changes
+        if: github.ref == 'refs/tags/[0-9]+.[0-9]+.[0-9]+'
+        working-directory: ${{ env.DOCS_TEMP_DIR }}
+        run: |
+          git config --global user.name "GitHub Actions"
+          git config --global user.email "[email protected]"
+          git add -A
+          if [[ "$(git status --porcelain)" ]]; then
+            git commit -m "Update documentation for $GITHUB_REF_NAME"
+            git push
+          else
+            echo "No changes to commit"
+          fi
+  publish-packages:
+    name: Publish packages
     if: github.ref == 'refs/tags/[0-9]+.[0-9]+.[0-9]+'
     runs-on: windows-latest
     environment: deploy