Add code highlighting feature

Author: ikoamu

README.md

@@ -76,3 +76,9 @@ jobs:
           org-roam-db-filename: <org-roam-filename>.db
           site-title: my org-roam!
 ```
+
+## code highlighting
+
+Sites generated by publish-org-roam will have code blocks highlighted.
+
+<img src="https://private-user-images.githubusercontent.com/38206334/316004679-b462de34-1153-4789-8c08-0d8dad486293.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.kSv3N7NyqKKjZZorj0qRauR4qPj5nwlZf-CCM9Yq3B8">