Update playground.md: project limit

Author: lionello

docs/providers/playground.md

@@ -4,10 +4,16 @@ description: The Defang Playground is a free tier that allows you to experiment
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-The Defang Playground is a free tier that allows you to experiment with Defang. The Playground is a shared that cannot be used to run production workloads. The Playground is a great way to get started with Defang and to experiment with the Defang CLI.
+The Defang Playground is a free tier that allows you to experiment with Defang. The Playground is a shared environment that should not be used to run production workloads. The Playground is a great way to get started with Defang using "1-click deploy" or to experiment with the Defang CLI.
 
-This page highlights architectural considerations when deploying to the playground and any differences you might encounter when deploying to the playground versus deploying to your own cloud account.
+This page highlights architectural considerations when deploying to the Playground and any differences you might encounter when deploying to the Playground versus deploying to your own cloud account.
+
+:::info The Playground allows only 1 deployed project at a time. Use the CLI `defang down` to tear down a project before deploying a new one. :::
 
 ## Overview
 
 Overall, the Defang Playground is very similar to deploying to your own cloud account. The Playground runs on a Defang-managed AWS account, so you can expect it to work similarly to deploying to [AWS](./aws/aws.md).
+
+### Managed services
+
+In essence, the Playground does not support any [managed storage](../concepts/managed-storage) services, ie. `x-defang-postgres` and `x-defang-redis` are ignored when deploying to the Playground. You can however run both postgres and redis as regular container services for testing purposes.