Allow allow extra directories in gh-pages branch

Don't clean the deployment branch from extra stuff at every deployment

Author: m-aciek

.github/workflows/update.yml

@@ -25,7 +25,7 @@ jobs:
         uses: JamesIves/github-pages-deploy-action@v4
         with:
           folder: build
-          clean: true
+          clean: false
           git-config-name: github-actions[bot]
           git-config-email: 41898282+github-actions[bot]@users.noreply.github.com
       - name: Debug index.html if pull request