Update README

Signed-off-by: Jael Gu <mengjia.gu@zilliz.com>

README.md

@@ -1,4 +1,4 @@
-# OpenAI Chat Completion
+# Dolly Generation
 
 *author: Jael*
 
@@ -22,16 +22,15 @@ Use the default model to continue the conversation from given messages.
 from towhee import pipe, ops
 
 p = (
-    pipe.input('messages')
-        .map('messages', 'answer', ops.LLM.Dolly())
-        .output('messages', 'answer')
+    pipe.input('question', 'docs', 'history')
+        .map(('question', 'docs', 'history'), 'prompt', ops.prompt.question_answer(llm_name='dolly'))
+        .map('prompt', 'answer', ops.LLM.Dolly())
+        .output('answer')
 )
 
-messages=[
-        {'question': 'Who won the world series in 2020?', 'answer': 'The Los Angeles Dodgers won the World Series in 2020.'},
-        {'question': 'Where was it played?'}
-    ]
-answer = p(messages)
+history=[('Who won the world series in 2020?', 'The Los Angeles Dodgers won the World Series in 2020.')]
+question = 'Where was it played?'
+answer = p(question, [], history)
 ```
 
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