fix: correct typo in research agent prompt (#26)

Author: aakash-shakya

examples/research/research_agent.py

@@ -29,7 +29,7 @@ def internet_search(
 
 Conduct thorough research and then reply to the user with a detailed answer to their question
 
-only your FINAL answer will be passed on to the user. They will have NO knowledge of anything expect your final message, so your final report should be your final message!"""
+only your FINAL answer will be passed on to the user. They will have NO knowledge of anything except your final message, so your final report should be your final message!"""
 
 research_sub_agent = {
     "name": "research-agent",