doc updates (#1639)

---------

Co-authored-by: vbarda <vadym@langchain.dev>

docs/docs/cloud/how-tos/same-thread.md

@@ -6,6 +6,8 @@ This means that you can run multiple agents on the same thread, which allows a d
 In this example, we will create two agents and then call them both on the same thread.
 You'll see that the second agent will respond using information from the [checkpoint](https://langchain-ai.github.io/langgraph/concepts/low_level/#checkpointer-state) generated in the thread by the first agent as context.
 
+## Setup
+
 === "Python"
 
     ```python
@@ -124,6 +126,10 @@ Output:
         }
     }
 
+## Run assistants on thread
+
+### Run OpenAI assistant
+
 We can now run the OpenAI assistant on the thread first.
 
 === "Python"
@@ -178,7 +184,7 @@ We can now run the OpenAI assistant on the thread first.
             "input": {
                 "messages": [
                     {
-                        "role": "human",
+                        "role": "user",
                         "content": "who made you?"
                     }
                 ]
@@ -218,6 +224,8 @@ Output:
     Receiving event of type: updates
     {'agent': {'messages': [{'content': 'I was created by OpenAI, a research organization focused on developing and advancing artificial intelligence technology.', 'additional_kwargs': {}, 'response_metadata': {'finish_reason': 'stop', 'model_name': 'gpt-4o-2024-05-13', 'system_fingerprint': 'fp_157b3831f5'}, 'type': 'ai', 'name': None, 'id': 'run-f5735b86-b80d-4c71-8dc3-4782b5a9c7c8', 'example': False, 'tool_calls': [], 'invalid_tool_calls': [], 'usage_metadata': None}]}}
 
+### Run default assistant
+
 Now, we can run it on the default assistant and see that this second assistant is aware of the initial question, and can answer the question, "and you?":
 
 === "Python"
@@ -266,7 +274,7 @@ Now, we can run it on the default assistant and see that this second assistant i
             "input": {
                 "messages": [
                     {
-                        "role": "human",
+                        "role": "user",
                         "content": "and you?"
                     }
                 ]