docs: Use voyage-law-2 in the examples (#20784)

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**Description:** In VoyageAI text-embedding examples use voyage-law-2
model


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2. an example notebook showing its use. It lives in
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docs/docs/integrations/document_transformers/voyageai-reranker.ipynb

@@ -84,7 +84,13 @@
    },
    "source": [
     "## Set up the base vector store retriever\n",
-    "Let's start by initializing a simple vector store retriever and storing the 2023 State of the Union speech (in chunks). We can set up the retriever to retrieve a high number (20) of docs."
+    "Let's start by initializing a simple vector store retriever and storing the 2023 State of the Union speech (in chunks). We can set up the retriever to retrieve a high number (20) of docs. You can use any of the following Embeddings models: ([source](https://docs.voyageai.com/docs/embeddings)):\n",
+    "\n",
+    "- `voyage-large-2` (default)\n",
+    "- `voyage-code-2`\n",
+    "- `voyage-2`\n",
+    "- `voyage-law-2`\n",
+    "- `voyage-lite-02-instruct`"
    ]
   },
   {
@@ -316,7 +322,7 @@
     "text_splitter = RecursiveCharacterTextSplitter(chunk_size=500, chunk_overlap=100)\n",
     "texts = text_splitter.split_documents(documents)\n",
     "retriever = FAISS.from_documents(\n",
-    "    texts, VoyageAIEmbeddings(model=\"voyage-2\")\n",
+    "    texts, VoyageAIEmbeddings(model=\"voyage-law-2\")\n",
     ").as_retriever(search_kwargs={\"k\": 20})\n",
     "\n",
     "query = \"What did the president say about Ketanji Brown Jackson\"\n",

docs/docs/integrations/text_embedding/voyageai.ipynb

@@ -27,7 +27,13 @@
    "id": "137cfde9-b88c-409a-9394-a9e31a6bf30d",
    "metadata": {},
    "source": [
-    "Voyage AI utilizes API keys to monitor usage and manage permissions. To obtain your key, create an account on our [homepage](https://www.voyageai.com). Then, create a VoyageEmbeddings model with your API key. Please refer to the documentation for further details on the available models: https://docs.voyageai.com/embeddings/"
+    "Voyage AI utilizes API keys to monitor usage and manage permissions. To obtain your key, create an account on our [homepage](https://www.voyageai.com). Then, create a VoyageEmbeddings model with your API key. You can use any of the following models: ([source](https://docs.voyageai.com/docs/embeddings)):\n",
+    "\n",
+    "- `voyage-large-2` (default)\n",
+    "- `voyage-code-2`\n",
+    "- `voyage-2`\n",
+    "- `voyage-law-2`\n",
+    "- `voyage-lite-02-instruct`"
    ]
   },
   {
@@ -38,7 +44,7 @@
    "outputs": [],
    "source": [
     "embeddings = VoyageAIEmbeddings(\n",
-    "    voyage_api_key=\"[ Your Voyage API key ]\", model=\"voyage-2\"\n",
+    "    voyage_api_key=\"[ Your Voyage API key ]\", model=\"voyage-law-2\"\n",
     ")"
    ]
   },