Update how-to-migrate-to-custom-neural-voice.md

Add China region for Custom Voice

Author: sally-baolian

articles/cognitive-services/Speech-Service/how-to-migrate-to-custom-neural-voice.md

@@ -74,6 +74,7 @@ If you've created a custom voice font, use the endpoint that you've created. You
 | Brazil South | `https://brazilsouth.voice.speech.microsoft.com/cognitiveservices/v1?deploymentId={deploymentId}` |
 | Canada Central | `https://canadacentral.voice.speech.microsoft.com/cognitiveservices/v1?deploymentId={deploymentId}` |
 | Central US | `https://centralus.voice.speech.microsoft.com/cognitiveservices/v1?deploymentId={deploymentId}` |
+| China East 2 | `https://chinaeast2.voice.speech.azure.cn/cognitiveservices/v1?deploymentId={deploymentId}` |
 | East Asia | `https://eastasia.voice.speech.microsoft.com/cognitiveservices/v1?deploymentId={deploymentId}` |
 | East US | `https://eastus.voice.speech.microsoft.com/cognitiveservices/v1?deploymentId={deploymentId}` |
 | East US 2 | `https://eastus2.voice.speech.microsoft.com/cognitiveservices/v1?deploymentId={deploymentId}` |