Add collab link (#11052)

docs/extras/guides/langsmith/walkthrough.ipynb

@@ -8,7 +8,7 @@
             },
             "source": [
                 "# LangSmith Walkthrough\n",
-                "[![Open In Collab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/langchain-ai/langchain/blob/master/./walkthrough.ipynb)\n",
+                "[![Open In Collab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/langchain-ai/langchain/blob/master/docs/extras/guides/langsmith/walkthrough.ipynb)\n",
                 "\n",
                 "LangChain makes it easy to prototype LLM applications and Agents. However, delivering LLM applications to production can be deceptively difficult. You will likely have to heavily customize and iterate on your prompts, chains, and other components to create a high-quality product.\n",
                 "\n",
@@ -786,4 +786,4 @@
     },
     "nbformat": 4,
     "nbformat_minor": 5
-}
+}