Update README with demo prerequisite

Author: benitav

demos/react-supabase-todolist/README.md

@@ -4,9 +4,12 @@
 
 Demo app demonstrating use of the [PowerSync SDK for Web](https://www.npmjs.com/package/@powersync/web) together with Supabase.
 
-A step-by-step guide on Supabase<>PowerSync integration is available [here](https://docs.powersync.com/integration-guides/supabase-+-powersync).
+## Run Demo
 
-## Getting Started
+Prerequisites:
+* To run this demo, you need to have properly configured Supabase and PowerSync projects. Follow the instructions in our Supabase<>PowerSync integration guide:
+  * [Configure Supabase](https://docs.powersync.com/integration-guides/supabase-+-powersync#configure-supabase)
+  * [Configure PowerSync](https://docs.powersync.com/integration-guides/supabase-+-powersync#configure-powersync)
 
 Switch into the demo's directory: