Add connection-string warnings

Author: dominicbetts

articles/iot-central/core/how-to-connect-iot-edge-transparent-gateway.md

@@ -18,6 +18,8 @@ IoT Edge supports the [*transparent* and *translation* gateway patterns](../../i
 
 :::image type="content" source="media/how-to-connect-iot-edge-transparent-gateway/edge-transparent-gateway.png" alt-text="Diagram that shows IoT Edge as a transparent gateway." border="false":::
 
+[!INCLUDE [iot-authentication-device-connection-string](../../../includes/iot-authentication-device-connection-string.md)]
+
 For simplicity, this article uses virtual machines to host the downstream and gateway devices. In a real scenario, the downstream device and gateway would run on physical devices on your local network.
 
 This article shows how to implement the scenario by using the IoT Edge 1.4 runtime.

articles/iot/set-up-environment.md

@@ -14,6 +14,8 @@ ms.devlang: azurecli
 
 Before you can complete any of the IoT Plug and Play quickstarts and tutorials, you need to configure an IoT hub and the Device Provisioning Service (DPS) in your Azure subscription. You'll also need local copies of the model files used by the sample applications and the Azure IoT explorer tool.
 
+[!INCLUDE [iot-authentication-service-connection-string](../../includes/iot-authentication-service-connection-string.md)]
+
 ## Prerequisites
 
 If you don't have an Azure subscription, create a [free account](https://azure.microsoft.com/free/?WT.mc_id=A261C142F) before you begin.

articles/iot/tutorial-migrate-device-to-module.md

@@ -14,6 +14,8 @@ ms.service: iot
 
 This tutorial shows you how to connect a generic IoT Plug and Play [module](../iot-hub/iot-hub-devguide-module-twins.md).
 
+[!INCLUDE [iot-authentication-device-connection-string](../../includes/iot-authentication-device-connection-string.md)]
+
 A device is an IoT Plug and Play device if it:
 
 * Publishes its model ID when it connects to an IoT hub.
@@ -35,7 +37,7 @@ To demonstrate how to implement an IoT Plug and Play module, this tutorial shows
 To complete this tutorial, install the following software in your local development environment:
 
 * Install the latest .NET for your operating system from [https://dot.net](https://dot.net).
-* [Git](https://git-scm.com/download/).
+* [Git](https://git-scm.com/downloads/).
 
 Use the Azure IoT explorer tool to add a new device called **my-module-device** to your IoT hub.