updated node version

Author: aidankmcalister

content/800-guides/420-clerk-astro.mdx

@@ -16,7 +16,7 @@ In this guide you'll wire Clerk into a brand-new [Astro](https://astro.build/) a
 
 ## Prerequisites
 
-- [Node.js 18+](https://nodejs.org)
+- [Node.js 20+](https://nodejs.org)
 - [Clerk account](https://clerk.com)
 - [ngrok account](https://ngrok.com)