Add link to Azure OpenAI provisioned offering updates

Author: brown9804

0_Azure/3_AzureAI/AIFoundry/demos/10_PTU_pricing_estimate/README.md

@@ -20,6 +20,7 @@ Last updated: 2025-12-29
 - [Input TPM per PTU](https://learn.microsoft.com/en-us/azure/ai-foundry/openai/how-to/provisioned-throughput-onboarding?view=foundry-classic#latest-azure-openai-models) - table
 - [Deployment types for Microsoft Foundry Models](https://learn.microsoft.com/en-us/azure/ai-foundry/foundry-models/concepts/deployment-types?view=foundry-classic#global-provisioned)
 - [Understanding costs associated with provisioned throughput units (PTU)](https://learn.microsoft.com/en-us/azure/ai-foundry/openai/how-to/provisioned-throughput-onboarding?view=foundry-classic)
+- [Azure OpenAI provisioned Managed offering updates](https://learn.microsoft.com/en-us/azure/ai-foundry/openai/concepts/provisioned-migration?view=foundry-classic)
 
 </details>