Update the Terraform deployment README.md to describe benefits and ri…

…sks of using Azure Cloud Shell (#541)

src/terraform/README.md

@@ -27,6 +27,10 @@ Read on to understand the [prerequisites](#Prerequisistes), how to get started,
 * The version of the [Terraform CLI](https://www.terraform.io/downloads.html) described in the [.devcontainer Dockerfile](../../../.devcontainer/Dockerfile)
 * An Azure Subscription(s) where you or an identity you manage has `Owner` [RBAC permissions](https://docs.microsoft.com/en-us/azure/role-based-access-control/built-in-roles#owner)
 
+<!-- markdownlint-disable MD013 -->
+> NOTE: Azure Cloud Shell is often our preferred place to deploy from because the AZ CLI and Terraform are already installed. However, sometimes Cloud Shell has different versions of the dependencies from what we have tested and verified, and sometimes there have been bugs in the Terraform Azure RM provider or the AZ CLI that only appear in Cloud Shell. If you are deploying from Azure Cloud Shell and see something unexpected, try the [development container](../../.devcontainer/README.md) or deploy from your machine using locally installed AZ CLI and Terraform. We welcome all feedback and [contributions](../../CONTRIBUTING.md), so if you see something that doesn't make sense, please [create an issue](../../issues/new/choose) or open a [discussion thread](../../discussions).
+<!-- markdownlint-enable MD013 -->
+
 Deploying to a Cloud other than Azure Commercial? This requires updating the `azurerm` provider block `environment` and `metadata_host` values. Checkout the [Deploying to Other Clouds](#Deploying-to-Other-Clouds) documentation.
 
 Looking to assign Azure Policy? This template supports assigning NIST 800-53 policies. See the [policies documentation](../../docs/policies.md) for more information.