docs: add note about SSR/SSG

Signed-off-by: David Dal Busco <david.dalbusco@outlook.com>

Author: peterpeterparker

docs/start-a-new-project.mdx

@@ -34,6 +34,12 @@ Supports Astro, Next.js, React, SvelteKit, Vue, and Angular.
 
 Prefer to begin with `npx create-next-app`, `npm create svelte@latest`, or any other starter you know well? Totally fine. Set up your frontend however you like, then bring in Juno afterward.
 
+:::tip[SSR not supported]
+
+Juno doesn’t yet support Server Side Rendering (SSR). Your frontend code should run on the client side. We recommend using Static Site Generation (SSG) or prerendering instead.
+
+:::
+
 Once your app is ready, head over to the [SDK Setup Guide](./setup-the-sdk.mdx) to:
 
 - Install the SDK