add links to Colab & NB viewer

Author: junefish

learn/generation/langchain/managing_rag_docs_langchain.ipynb

@@ -1,3 +1,12 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "[![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/pinecone-io/examples/blob/master/learn/generation/langchain/managing_rag_docs_langchain.ipynb) [![Open nbviewer](https://raw.githubusercontent.com/pinecone-io/examples/master/assets/nbviewer-shield.svg)](https://nbviewer.org/github/pinecone-io/examples/blob/master/learn/generation/langchain/managing_rag_docs_langchain.ipynb)"
+   ]
+  },
 {
   "nbformat": 4,
   "nbformat_minor": 0,
@@ -379,4 +388,4 @@
       ]
     }
   ]
-}
+}