Update openai-embeddings.adoc

Fixed small error in OpenAiChatOptions implementation documentation

spring-ai-docs/src/main/antora/modules/ROOT/pages/api/embeddings/openai-embeddings.adoc

@@ -157,7 +157,7 @@ Next, create an `OpenAiEmbeddingClient` instance and use it to compute the simil
 var openAiApi = new OpenAiApi(System.getenv("OPENAI_API_KEY"));
 
 var embeddingClient = new OpenAiEmbeddingClient(openAiApi)
-    .withDefaultOptions(OllamaOptions.create()
+    .withDefaultOptions(OpenAiChatOptions.build()
         .withModel("text-embedding-ada-002")
         .withUser("user-6")
         .build());