docs: use dedicated embedding model for ollama (#745)

apps/docs/docs/modules/embeddings/available_embeddings/ollama.md

 # Ollama
 
-To use Ollama embeddings, you need to import `Ollama` from `llamaindex`.
+To use Ollama embeddings, you need to import `OllamaEmbedding` from `llamaindex`.
+
+Note that you need to pull the embedding model first before using it.
+
+In the example below, we're using the [`nomic-embed-text`](https://ollama.com/library/nomic-embed-text) model, so you have to call:
+
+```shell
+ollama pull nomic-embed-text
+```
 
 ```ts
-import { Ollama, Settings } from "llamaindex";
+import { OllamaEmbedding, Settings } from "llamaindex";
 
-Settings.embedModel = new Ollama();
+Settings.embedModel = new OllamaEmbedding({ model: "nomic-embed-text" });
 
 const document = new Document({ text: essay, id_: "essay" });
 

examples/ollama.ts

+import { OllamaEmbedding } from "llamaindex";
 import { Ollama } from "llamaindex/llm/ollama";
 
 (async () => {
   const llm = new Ollama({ model: "llama3" });
+  const embedModel = new OllamaEmbedding({ model: "nomic-embed-text" });
   {
     const response = await llm.chat({
       messages: [{ content: "Tell me a joke.", role: "user" }],
@@ -35,7 +37,7 @@ import { Ollama } from "llamaindex/llm/ollama";
     console.log(); // newline
   }
   {
-    const embedding = await llm.getTextEmbedding("Hello world!");
+    const embedding = await embedModel.getTextEmbedding("Hello world!");
     console.log("Embedding:", embedding);
   }
 })();

package.json

@@ -33,7 +33,7 @@
     "turbo": "^1.13.2",
     "typescript": "^5.4.5"
   },
-  "packageManager": "pnpm@9.0.4",
+  "packageManager": "pnpm@9.0.5",
   "pnpm": {
     "overrides": {
       "trim": "1.0.1",