Create Langfuse deepagents integration guide (#2243)

* Add Langchain DeepAgents integration notebook

Co-authored-by: jannik <[email protected]>

* push

---------

Co-authored-by: Cursor Agent <[email protected]>

Author: jannikmaierhoefer

cookbook/_routes.json

@@ -19,6 +19,11 @@
     "docsPath": null,
     "isGuide": true
   },
+  {
+    "notebook": "integration_langchain_deepagents.ipynb",
+    "docsPath": "integrations/frameworks/langchain-deepagents",
+    "isGuide": false
+  },
   {
     "notebook": "example_llm_security_monitoring.ipynb",
     "docsPath": null,