docs: add a how to for multi-agent network (#2675)

docs/docs/how-tos/index.md

@@ -91,6 +91,12 @@ These how-to guides show common patterns for tool calling with LangGraph:
 - [How to view and update state in subgraphs](subgraphs-manage-state.ipynb)
 - [How to transform inputs and outputs of a subgraph](subgraph-transform-state.ipynb)
 
+### Multi-agent
+
+- [How to build a multi-agent network](multi-agent-network.ipynb)
+
+See the [multi-agent tutorials](../tutorials/index.md#multi-agent-systems) for implementations of other multi-agent architectures.
+
 ### State Management
 
 - [How to use Pydantic model as state](state-model.ipynb)

docs/mkdocs.yml

@@ -199,6 +199,8 @@ nav:
             - how-tos/subgraph.ipynb
             - how-tos/subgraphs-manage-state.ipynb
             - how-tos/subgraph-transform-state.ipynb
+        - Multi-agent:
+            - how-tos/multi-agent-network.ipynb
         - State Management:
             - State Management: how-tos#state-management
             - how-tos/state-model.ipynb