docs(srv): add content on serverless / CR namespaces behavior MTA-5959

Author: SamyOubouaziz

pages/serverless-containers/faq.mdx

@@ -173,6 +173,20 @@ Integration is straightforward. Serverless Functions and Containers can be trigg
 
 You can copy an image from an external registry using the Docker CLI, or open source third-party tools such as [Skopeo](https://github.com/containers/skopeo). Refer to the [dedicated documentation](/serverless-containers/api-cli/migrate-external-image-to-scaleway-registry/) for more information.
 
+### How do Serverless Containers namespaces and Container Registry namespaces interact?
+
+Serverless Containers namespaces and Container Registry namespaces observe the following behaviors:
+
+- Creating a Serverless Containers namespace implicitly creates an empty Container Registry namespace.
+
+- Creating a Container Registry namespace **does not** create a Serverless Containers namespace.
+
+- Serverless Containers and Container Registry namespace are not linked.
+
+- With Serverless Containers, you can use images from any Container Registry namespace, as long as they are in the same [Project](/organizations-and-projects/concepts/#project).
+
+- If you delete The Container Registry namespace associated with a Serverless Containers namespace, it will be created again when deploying a container within this Serverless Containers namespace.
+
 ### How do Serverless Containers health checks work ?
 
 A Serverless Container is set to `ready` once the specified port is correctly bound to the container, and will start receiving traffic. If your application needs to perform some tasks before receiving traffic (e.g. connect to a database), it is important to run them before binding to the port (starting the webserver).

pages/serverless-containers/how-to/create-manage-delete-containers-namespace.mdx

@@ -33,6 +33,10 @@ This page shows you how to create and manage a Serverless Containers namespace.
     - Verify the **estimated cost**.
 4. Click **Create namespace only** to finish, or click **Create namespace and add container** if you want to [deploy a container](/serverless-containers/how-to/deploy-container/) next.
 
+<Message type="tip">
+Refer to the [dedicated FAQ](/serverless-containers/faq/#how-do-serverless-containers-namespaces-and-container-registry-namespaces-interact) for more information on how Serverless Containers namespaces and Container Registry namespaces interact.
+</Message>
+
 ## Managing a Serverless Containers namespace
 
 ### Generating and managing access tokens

pages/serverless-functions/faq.mdx

@@ -190,6 +190,16 @@ There are [several ways to deploy Serverless Functions](/serverless-functions/re
 
 Integration is straightforward. Serverless Functions and Containers can be triggered by events from [Queues](/messaging/concepts/#queues) and [Topics and Events](/messaging/concepts/#topics-and-events), and can easily communicate with services like [Managed Databases](/managed-databases-for-postgresql-and-mysql/) or [Serverless databases](/serverless-sql-databases/). [Serverless Jobs](/serverless-jobs/) can pull data from [Object Storage](/object-storage/), or output processed results into a database. With managed connectors, APIs, and built-in integrations, linking to the broader Scaleway ecosystem is seamless.
 
+### How do Serverless Functions namespaces and Container Registry namespaces interact?
+
+Serverless Functions namespaces and Container Registry namespaces observe the following behaviors:
+
+- Creating a Serverless Functions namespace implicitly creates a Container Registry namespace. When a Serverless Function is deployed, the built image will be stored in the Container Registry namespace created.
+
+- Creating a Container Registry namespace **does not** create a Serverless Functions namespace.
+
+- If you delete The Container Registry namespace associated with a Serverless Functions namespace, it will be created again when deploying a function within this Serverless Functions namespace.
+
 ### How can I check build errors?
 
 Some Serverless runtimes (ex: `Go`, `Rust`) will compile your code in order to make your function executable.

pages/serverless-functions/how-to/create-manage-delete-functions-namespace.mdx

@@ -36,6 +36,9 @@ This page shows you how to create, manage, and delete a Functions namespace usin
     - Set optional secret environment variables. **Secrets** are environment variables which are injected into your function and stored securely, but not displayed in the console after initial validation. Add a **key** and a **value**.
 4. Click **Create namespace only** to finish, or click **Create namespace and add a function** if you want to [create a function](/serverless-functions/how-to/create-a-function/) next.
 
+<Message type="tip">
+Refer to the [dedicated FAQ](/serverless-functions/faq/#how-do-serverless-containers-namespaces-and-container-registry-namespaces-interact) for more information on how Serverless Functions namespaces and Container Registry namespaces interact.
+</Message>
 
 ## Managing a Serverless Functions namespace