docs: update multi_modal_RAG_chroma.ipynb (#14602)

seperate -> separate

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cookbook/multi_modal_RAG_chroma.ipynb

@@ -42,7 +42,7 @@
     "* We will use Open Clip multi-modal embeddings.\n",
     "* We will use [Chroma](https://www.trychroma.com/) with support for multi-modal.\n",
     "\n",
-    "A seperate cookbook highlights `Options 2 and 3` [here](https://github.com/langchain-ai/langchain/blob/master/cookbook/Multi_modal_RAG.ipynb).\n",
+    "A separate cookbook highlights `Options 2 and 3` [here](https://github.com/langchain-ai/langchain/blob/master/cookbook/Multi_modal_RAG.ipynb).\n",
     "\n",
     "![chroma_multimodal.png](attachment:1920fda3-1808-407c-9820-f518c9c6f566.png)\n",
     "\n",