Add excerpt

Author: adamwathan

src/pages/whats-new-in-tailwindcss-on-youtube/index.mdx

@@ -10,6 +10,14 @@ export const meta = {
   discussion: 'https://github.com/tailwindlabs/tailwindcss/discussions/2441',
 }
 
+<!--excerpt-->
+
+A lot of cool stuff has been added to Tailwind since the last time we published any screencasts, so we thought it would be a great idea to record a little series that covers all of the new additions.
+
+["What's new in Tailwind CSS?"](https://www.youtube.com/watch?v=b-hrxkgkG-s&list=PL5f_mz_zU5eV0_7udNKr3qffGCkJ4Avb_) is a series of 12 short videos that teach you everything you need to know about some of our favorite new Tailwind features.
+
+<!--/excerpt-->
+
 A lot of cool stuff has been added to Tailwind since the last time we published any screencasts, so we thought it would be a great idea to record a little series that covers all of the new additions.
 
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