Add deploy step for github pages

Author: HiranChaudhuri

.github/workflows/build-all.yml

@@ -310,3 +310,21 @@ jobs:
             artifacts/oolite-documentation-nightly/oolite-*.tgz
             artifacts/oolite-linux-nightly/oolite-*.tgz
             artifacts/oolite-windows-nightly/OoliteInstall*.exe
+
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    needs: build-doxygen
+    runs-on: ubuntu-latest
+
+    # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+    permissions:
+      contents: read
+      pages: write
+      id-token: write
+
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v2