Update responses.md typo in reference link anchor

existing link https://learn.microsoft.com/en-us/azure/ai-services/openai/reference-preview-latest?#responses-api---create hits a redirect to https://learn.microsoft.com/en-us/azure/ai-foundry/openai/reference-preview-latest#responses-api---create where anchor "#responses-api---create" doesn't exist. 
#create-response seems to be the (new) valid target

Author: Guillaume-Fourrat

articles/ai-foundry/openai/how-to/responses.md

@@ -70,7 +70,7 @@ Not every model is available in the regions supported by the responses API. Chec
 
 ### Reference documentation
 
-- [Responses API reference documentation](/azure/ai-services/openai/reference-preview-latest?#responses-api---create)
+- [Responses API reference documentation](/azure/ai-services/openai/reference-preview-latest?#create-response)
 
 ## Getting started with the responses API