chore(docs): update docus

Author: yaozheng-fang

docs/content/6.memory/3.long-term-memory.md

@@ -12,39 +12,47 @@ VeADK 的长期记忆通常存储在数据库中，通过如下方式定义一
 ```python
 from veadk.memory.long_term_memory import LongTermMemory
 
-long_term_memory = LongTermMemory()
+# 由于长期记忆需要构建索引，因此你必须在初始化长期记忆时定义 `app_name` 以及 `user_id`
+long_term_memory = LongTermMemory(app_name="my_app_name", user_id="user_id")
 ```
 
 通过如下例子说明长期记忆：
 
 以下示例展示了如何在 VeADK 中使用长期记忆实现跨会话的信息保留与调用。开发者可以通过 `save_session_to_long_term_memory` 方法，将某一会话中的知识性信息存入长期记忆存储后端。在新的会话中，即使上下文为空，Agent 依然能够基于长期记忆准确回忆并回答相关问题。
 
 ```python
+import asyncio
+
 from veadk import Agent, Runner
 from veadk.memory.long_term_memory import LongTermMemory
-from veadk.memory.short_term_memory import ShortTermMemory
 
-session_id = "..."
-new_session_id = "..."
+app_name = "ltm_demo"
+user_id = "temp_user"
+
+teaching_session_id = "teaching_session"
+student_session_id = "student_session"
+
+long_term_memory = LongTermMemory(backend="local", app_name=app_name, user_id=user_id)
 
-long_term_memory = LongTermMemory(backend=...)  # default backend is `opensearch`
-agent = Agent(long_term_memory=long_term_memory) # agent with long term memort backend
+agent = Agent(long_term_memory=long_term_memory)
 
 runner = Runner(
     agent=agent,
-    app_name="...",
-    user_id="...",
-    short_term_memory=ShortTermMemory(),
+    app_name=app_name,
+    user_id=user_id,
 )
-teaching_prompt = "..."
-await runner.run(messages=teaching_prompt, session_id=session_id)
+
+teaching_prompt = "My secret is 0xabcd"
+asyncio.run(runner.run(messages=teaching_prompt, session_id=teaching_session_id))
 
 # save the teaching prompt and answer in long term memory
-await runner.save_session_to_long_term_memory(session_id=session_id)
+asyncio.run(runner.save_session_to_long_term_memory(session_id=teaching_session_id))
 
 # now, let's validate this in a new session
-student_prompt = "..."
-response = await runner.run(messages=student_prompt, session_id=new_session_id)
+student_prompt = "What is my secret?"
+response = asyncio.run(
+    runner.run(messages=student_prompt, session_id=student_session_id)
+)
 print(response)
 ```