add(feat): Text Embeddings by Cloudflare Workers AI (#14220)

Add [Text Embeddings by Cloudflare Workers
AI](https://developers.cloudflare.com/workers-ai/models/text-embeddings/).
It's a new integration.
Trying to align it with its langchain-js version counterpart
[here](https://api.js.langchain.com/classes/embeddings_cloudflare_workersai.CloudflareWorkersAIEmbeddings.html).
- Dependencies: N/A
- Done `make format` `make lint` `make spell_check` `make
integration_tests` and all my changes was passed

docs/docs/integrations/text_embedding/cloudflare_workersai.ipynb

@@ -0,0 +1,125 @@
+{
+ "cells": [
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "id": "59428e05",
+   "metadata": {},
+   "source": [
+    "# Text Embeddings on Cloudflare Workers AI\n",
+    "\n",
+    "[Cloudflare AI document](https://developers.cloudflare.com/workers-ai/models/text-embeddings/) listed all text embeddings models available.\n",
+    "\n",
+    "Both Cloudflare account ID and API token are required. Find how to obtain them from [this document](https://developers.cloudflare.com/workers-ai/get-started/rest-api/).\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "92c5b61e",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from langchain.embeddings.cloudflare_workersai import CloudflareWorkersAIEmbeddings"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "f60023b8",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import getpass\n",
+    "\n",
+    "my_account_id = getpass.getpass(\"Enter your Cloudflare account ID:\\n\\n\")\n",
+    "my_api_token = getpass.getpass(\"Enter your Cloudflare API token:\\n\\n\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "062547b9",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "(384, [-0.033627357333898544, 0.03982774540781975, 0.03559349477291107])"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "embeddings = CloudflareWorkersAIEmbeddings(\n",
+    "    account_id=my_account_id,\n",
+    "    api_token=my_api_token,\n",
+    "    model_name=\"@cf/baai/bge-small-en-v1.5\",\n",
+    ")\n",
+    "# single string embeddings\n",
+    "query_result = embeddings.embed_query(\"test\")\n",
+    "len(query_result), query_result[:3]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "e1dcc4bd",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "(3, 384)"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# string embeddings in batches\n",
+    "batch_query_result = embeddings.embed_documents([\"test1\", \"test2\", \"test3\"])\n",
+    "len(batch_query_result), len(batch_query_result[0])"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "52de8b88",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.18"
+  },
+  "vscode": {
+   "interpreter": {
+    "hash": "7377c2ccc78bc62c2683122d48c8cd1fb85a53850a1b1fc29736ed39852c9885"
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}