Add Prompt Revision for Empty Response

This is the working prompt fix suggested by

@zuxin-llm
from discussion #2.

README.md

@@ -110,6 +110,7 @@ pip install transformers>=4.41.0
 
 We use the following example to illustrate how to use our model to perform function-calling tasks. 
 Please note that, our model works best with our provided prompt format. 
+In case the provided prompt returns an empty result on a reasonable query, try removing the following from the prompt: ```If no function call is needed, please make tool_calls an empty list '[]'.```
 It allows us to extract JSON output that is similar to the [function-calling mode of ChatGPT](https://platform.openai.com/docs/guides/function-calling).
 
 ````python