fix: some image loading

src/helpers/markdown.ts

@@ -4,6 +4,7 @@ const parser = new MarkdownIt();
 export function readDuration(markdown: string): number | undefined {
   if (!markdown) return;
   const words = markdown.split(" ")?.filter(Boolean)?.length;
+  if (!words) return;
   return words && Math.round(words / 250);
 }