fix the typo

Author: jayendranarumugam

articles/ai-services/openai/how-to/prompt-caching.md

@@ -39,7 +39,7 @@ For a request to take advantage of prompt caching the request must be both:
 - A minimum of 1,024 tokens in length.
 - The first 1,024 tokens in the prompt must be identical.
 
-When a match is found between the token computations in a prompt and the current content of the prompt cache, it's referred to as a cache hit. Cache hits will show up as [`cached_tokens`](/azure/ai-services/openai/reference-preview#cached_tokens) under [`prompt_token_details`](/azure/ai-services/openai/reference-preview#properties-for-prompt_tokens_details) in the chat completions response.
+When a match is found between the token computations in a prompt and the current content of the prompt cache, it's referred to as a cache hit. Cache hits will show up as [`cached_tokens`](/azure/ai-services/openai/reference-preview#cached_tokens) under [`prompt_tokens_details`](/azure/ai-services/openai/reference-preview#properties-for-prompt_tokens_details) in the chat completions response.
 
 ```json
 {
@@ -85,4 +85,4 @@ To improve the likelihood of cache hits occurring, you should structure your req
 
 ## Can I disable prompt caching?
 
-Prompt caching is enabled by default for all supported models. There is no opt-out support for prompt caching. 
+Prompt caching is enabled by default for all supported models. There is no opt-out support for prompt caching.