docs: add link to api references for create_react_agent (#759)

docs/docs/how-tos/index.md

@@ -9,7 +9,7 @@ Welcome to the LangGraph how-to guides! These guides provide practical, step-by-
 
 ## Basics
 
-The core guides show how to address common needs when building out AI workflows, with special focus placed on [ReAct](https://arxiv.org/abs/2210.03629)-style agents with [tool calling](https://python.langchain.com/docs/modules/model_io/chat/function_calling/) (agents that <strong>Re</strong>ason and **Act** to accomplish tasks).
+These guides show how to address common needs when building out AI workflows, with special focus placed on [ReAct](https://arxiv.org/abs/2210.03629)-style agents with [tool calling](https://python.langchain.com/docs/modules/model_io/chat/function_calling/) (agents that <strong>Re</strong>ason and **Act** to accomplish tasks).
 
 - [How to create a ReAct agent](create-react-agent.ipynb)
 - [How to add persistence ("memory") to your graph](persistence.ipynb)

examples/create-react-agent.ipynb

@@ -131,6 +131,14 @@
     "### Define the graph"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "2a2da4e4",
+   "metadata": {},
+   "source": [
+    "We're going to use a prebuilt implementation of ReAct agent included with `langgraph` library - [`create_react_agent`](https://langchain-ai.github.io/langgraph/reference/prebuilt/#create_react_agent)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 4,