Update DeploymentGuide.md for local development & debugging instructions

Author: Prajwal-Microsoft

docs/DeploymentGuide.md

@@ -195,7 +195,7 @@ Once you've opened the project in [Codespaces](#github-codespaces), [Dev Contain
      - Follow steps in [Delete Resource Group](./DeleteResourceGroup.md) if your deployment fails and/or you need to clean up the resources.
 
 ## Environment configuration for local development & debugging
-> Set APP_ENV in your .env file to control Azure authentication. Use dev to enable to use Azure CLI credential, Prod to enable Managed Identity (for production). **Ensure you're logged in via az login when using dev in local**.
+> Set APP_ENV in your .env file to control Azure authentication. Set the environment variable to dev to use Azure CLI credentials, or to prod to use Managed Identity for production. **Ensure you're logged in via az login when using dev in local**.
 To configure your environment, follow these steps:
 1. Navigate to the `src` folder.
 2. Create a `.env` file based on the `.env.sample` file.