add auto keywords and auto-question (#2965)

### What problem does this PR solve?

#2687

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

rag/nlp/__init__.py

@@ -570,14 +570,3 @@ def naive_merge_docx(sections, chunk_token_num=128, delimiter="\n。；！？"):
 
     return cks, images
 
-
-def keyword_extraction(chat_mdl, content):
-    prompt = """
-You're a question analyzer. 
-1. Please give me the most important keyword/phrase of this question.
-Answer format: (in language of user's question)
- - keyword: 
-"""
-    kwd = chat_mdl.chat(prompt, [{"role": "user",  "content": content}], {"temperature": 0.2})
-    if isinstance(kwd, tuple): return kwd[0]
-    return kwd