doc update

doc/q_chat.md

@@ -1,16 +1,16 @@
 ## q_chat
 the q_chat script allows you to chat with the Amazon Q assistant from the command line.
-The question prompt is sent to the Q application (defined by its id) and a json structure is returned.
+The question prompt is sent to the Q application (defined by its id) and a json structure is returned. 
+It is also possible to attach a file to the chat question.
 
 If you don't provide a conversation id, Amazon Q will assume that you start a new conversation with him.
 If you provide a conversation id (obtained from a previous exchange in field "conversationId") and the 
 message id - as last returned systemMessageId" (see example below) - of last the assistant response, Q will 
 assume that you continue this conversation and restore the context of this precedent conversation to 
 continue the chat based on the conversation context.
 
-This script is based on the chat_sync() API provided by the Amazon Q service.
-
-The userid should be one of the user created in the Q application as per documentation
+This script is based on the [boto3("qbusiness").chat_sync() API](https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/qbusiness/client/chat_sync.html) provided by the Amazon Q service. The userid should be one of 
+the user created in the Q application as per documentation.
 
 ### Usage 
 Use with a simple text prompt