Deploy to existing (#637)

Author: pamelafox

README.md

@@ -50,7 +50,7 @@ The repo includes sample data so it's ready to try end to end. In this sample ap
 
 * **Azure account**. If you're new to Azure, [get an Azure account for free](https://azure.microsoft.com/free/cognitive-search/) and you'll get some free Azure credits to get started.
 * **Azure subscription with access enabled for the Azure OpenAI service**. You can request access with [this form](https://aka.ms/oaiapply). If your access request to Azure OpenAI service doesn't match the [acceptance criteria](https://learn.microsoft.com/legal/cognitive-services/openai/limited-access?context=%2Fazure%2Fcognitive-services%2Fopenai%2Fcontext%2Fcontext), you can use [OpenAI public API](https://platform.openai.com/docs/api-reference/introduction) instead. Learn [how to switch to an OpenAI instance](#switching-from-an-azure-openai-endpoint-to-an-openai-instance).
-* **Azure account permissions**: Your Azure account must have `Microsoft.Authorization/roleAssignments/write` permissions, such as [Role Based Access Control Administrator](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#role-based-access-control-administrator-preview), [User Access Administrator](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#user-access-administrator), or [Owner](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#owner).
+* **Azure account permissions**: Your Azure account must have `Microsoft.Authorization/roleAssignments/write` permissions, such as [Role Based Access Control Administrator](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#role-based-access-control-administrator-preview), [User Access Administrator](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#user-access-administrator), or [Owner](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#owner). If you don't have subscription-level permissions, you must be granted [RBAC](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#role-based-access-control-administrator-preview) for an existing resource group and [deploy to that existing group](#existing-resource-group).
 
 ## Azure deployment
 
@@ -126,6 +126,11 @@ It will look like the following:
 
 If you already have existing Azure resources, you can re-use those by setting `azd` environment values.
 
+#### Existing resource group
+
+1. Run `azd env set AZURE_RESOURCE_GROUP {Name of existing resource group}`
+1. Run `azd env set AZURE_LOCATION {Location of existing resource group}`
+
 #### Existing OpenAI resource
 
 1. Run `azd env set AZURE_OPENAI_SERVICE {Name of existing OpenAI service}`