Correct supported regions list in re-use-foundry-project.md

Align the listed regions with the @Allowed list enforced by
infra/main.bicep and infra/main_custom.bicep for the unified AI
Services account (japaneast, southeastasia, uksouth added;
northcentralus, switzerlandnorth, westus2 removed).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Harsh-Microsoft

docs/re-use-foundry-project.md

@@ -6,7 +6,7 @@ To configure your environment to use an existing Azure AI Foundry Project, follo
 > **⚠️ Region requirement**
 >
 > The existing Foundry project must reside in a region that supports **both** the GPT model deployed by this accelerator (default `gpt-5.1` with `GlobalStandard` deployment type) **and** Azure AI Content Understanding (GA).<br>
-> Supported regions: `australiaeast`, `eastus`, `eastus2`, `northcentralus`, `southcentralus`, `swedencentral`, `switzerlandnorth`, `westeurope`, `westus`, `westus2`, `westus3`.<br>
+> Supported regions: `australiaeast`, `eastus`, `eastus2`, `japaneast`, `southcentralus`, `southeastasia`, `swedencentral`, `uksouth`, `westeurope`, `westus`, `westus3`.<br>
 > If the existing project is in a different region, deployment will fail or the application will not work correctly.
 
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