Don't render title when it's null

client/coral-plugin-infobox/Markdown.js

@@ -5,7 +5,7 @@ const renderer = new marked.Renderer();
 
 // Set link target to `_parent` to work properly in an embed.
 renderer.link = (href, title, text) =>
-  `<a target="_parent" href="${href}" title="${title}">${text}</a>`;
+  `<a target="_parent" href="${href}" ${title ? `title="${title}"` : ''}>${text}</a>`;
 
 marked.setOptions({renderer});