docs: reorganize API refs (#1884)

docs/docs/reference/prebuilt.md

@@ -1,67 +1,18 @@
 # Prebuilt
 
-## create_react_agent
+::: langgraph.prebuilt.chat_agent_executor
+    options:
+      members:
+        - create_react_agent
 
-```python
-from langgraph.prebuilt import create_react_agent
-```
+::: langgraph.prebuilt.tool_node
+    options:
+      members:
+        - ToolNode
+        - InjectedState
+        - tools_condition
 
-::: langgraph.prebuilt.create_react_agent
-
-## ToolNode
-
-```python
-from langgraph.prebuilt import ToolNode
-```
-
-::: langgraph.prebuilt.ToolNode
-    handler: python
-    
-
-## ToolExecutor
-
-```python
-from langgraph.prebuilt import ToolExecutor
-```
-
-::: langgraph.prebuilt.ToolExecutor
-    handler: python
-    
-
-## ToolInvocation
-
-```python
-from langgraph.prebuilt import ToolInvocation
-```
-
-::: langgraph.prebuilt.ToolInvocation
-    handler: python
-    heading_level: 4
-
-
-
-## `tools_condition`
-
-```python
-from langgraph.prebuilt import tools_condition
-```
-
-::: langgraph.prebuilt.tools_condition
-
-
-## ValidationNode
-
-```python
-from langgraph.prebuilt import ValidationNode
-```
-
-::: langgraph.prebuilt.ValidationNode
-
-## InjectedState
-
-```python
-from langgraph.prebuilt import InjectedState
-```
-
-::: langgraph.prebuilt.InjectedState
-    handler: python
+::: langgraph.prebuilt.tool_validator
+    options:
+      members:
+        - ValidationNode