README: Use .app instead of .com for demo link

FinnWoelm · FinnWoelm · commit 5c78a88f5b79 · 2020-06-04T21:31:23.000+02:00
Netlify sites are now hosted as .app rather than .com: https://community.netlify.com/t/changes-coming-to-netlify-site-urls/8918
diff --git a/README.md b/README.md
@@ -4,7 +4,7 @@
 
 This is a demo of a NextJS application with Server-Side Rendering (SSR).
 
-View the demo: [https://next-on.netlify.com](https://next-on.netlify.com)
+View the demo: [https://next-on.netlify.app](https://next-on.netlify.app)
 
 The demo is hosted on Netlify. Minimal configuration required thanks to [the next-on-netlify npm package](https://www.npmjs.com/package/next-on-netlify). next-on-netlify makes server-side rendering possible by using Netlify functions under the hood.
 
