Update documentation of Docker images (#440)

src/documentation/articles/docker.md

@@ -7,4 +7,9 @@ _description: Describes the Docker images of .NET suite for Apache Kafka
 
 .NET suite for Apache Kafka comes with some ready made Docker images:
 - KNet CLI: see [KNet CLI usage](usageCLI.md)
-- KNet Connect: see [KNet Connect usage](usageConnect.md)
+- KNet Connect: see [KNet Connect usage](usageConnect.md)
+
+> [!IMPORTANT]
+> The Docker images produced from this repository uses, as base image, the one available at mcr.microsoft.com/dotnet/runtime:6.0 (latest is mcr.microsoft.com/dotnet/runtime:6.0-jammy). Within [GitHub Container Registry](https://github.com/microsoft/containerregistry) you can find many legal information, specifically read carefully the following before use the image:
+> - [Container Images Legal Notice](https://github.com/microsoft/containerregistry/blob/39d2e014897475ef6cdb08e29c08645f53f0dc93/legal/Container-Images-Legal-Notice.md): maybe an updated verion is available at https://github.com/microsoft/containerregistry/blob/main/legal/Container-Images-Legal-Notice.md
+> - [Linux-Legal-Metadata](https://github.com/microsoft/containerregistry/blob/39d2e014897475ef6cdb08e29c08645f53f0dc93/legal/Linux-Legal-Metadata.md): maybe a updated verion is available at https://github.com/microsoft/containerregistry/blob/main/legal/Linux-Legal-Metadata.md