chore(prompt_tools): add support for querying the clients directory (#4038)

Author: wsxiaoys

ee/tabby-webserver/src/service/answer/prompt_tools.rs

@@ -49,6 +49,7 @@ Here's a few examples:
 "How many python files is in the codebase?" -> FILE_LIST
 "Which file contains main function?" -> SNIPPET
 "What does this repository do?" -> FILE_LIST
+"What does the `clients` directory do?" -> FILE_LIST
 
 Here's the original question:
 {question}