Add mention about standard agent setup (Azure#51029)

Author: nick863

sdk/ai/Azure.AI.Agents.Persistent/README.md

@@ -789,6 +789,7 @@ Assert.AreEqual(
     run.LastError?.Message);
 ```
 
+**Note:** The Azure Function may be only used in standard agent setup. Please follow the [instruction](https://github.com/azure-ai-foundry/foundry-samples/tree/main/samples/microsoft/infrastructure-setup/41-standard-agent-setup) to deploy an agent, capable of calling Azure Functions.
 To make a function call we need to create and deploy the Azure function. In the code snippet below, we have an example of function on C# which can be used by the code above.
 
 ```C#

sdk/ai/Azure.AI.Agents.Persistent/samples/Sample2_PersistentAgents_Azure_Functions.md

@@ -55,6 +55,7 @@ namespace FunctionProj
 
 In this code we define function input and output class: `Arguments` and `Response` respectively. These two data classes will be serialized in JSON. It is important that these both contain field `CorrelationId`, which is the same between input and output.
 
+**Note:** The Azure Function may be only used in standard agent setup. Please follow the [instruction](https://github.com/azure-ai-foundry/foundry-samples/tree/main/samples/microsoft/infrastructure-setup/41-standard-agent-setup) to deploy an agent, capable of calling Azure Functions.
 In our example the function will be stored in the storage account, created with the AI hub. For that we need to allow key access to that storage. In Azure portal go to Storage account > Settings > Configuration and set "Allow storage account key access" to Enabled. If it is not done, the error will be displayed "The remote server returned an error: (403) Forbidden." To create the function resource that will host our function, install [azure-cli](https://pypi.org/project/azure-cli/) python package and run the next command:
 
 ```shell