fix: copy styles from .reveal-md

Author: vvscode

.github/workflows/deploy-to-gh-pages.yml

@@ -20,6 +20,7 @@ jobs:
           npx reveal-md lessons/ --static dist
           rsync -a -r lessons/ dist/
           cp -r plugins dist/_assets/
+          cp -r .reveal-md dist/_assets/
 
       - name: Deploy
         # https://github.com/marketplace/actions/deploy-to-github-pages