doc: provide a workable guideline update for ollama user (bytedance#323)

Author: superryanguo

docs/configuration_guide.md

@@ -61,12 +61,13 @@ BASIC_MODEL:
 ### How to use Ollama models?
 
 DeerFlow supports the integration of Ollama models. You can refer to [litellm Ollama](https://docs.litellm.ai/docs/providers/ollama). <br>
-The following is a configuration example of `conf.yaml` for using Ollama models:
+The following is a configuration example of `conf.yaml` for using Ollama models(you might need to run the 'ollama serve' first):
 
 ```yaml
 BASIC_MODEL:
-  model: "ollama/ollama-model-name"
-  base_url: "http://localhost:11434" # Local service address of Ollama, which can be started/viewed via ollama serve
+  model: "model-name"  # Model name, which supports the completions API(important), such as: qwen3:8b, mistral-small3.1:24b, qwen2.5:3b
+  base_url: "http://localhost:11434/v1" # Local service address of Ollama, which can be started/viewed via ollama serve
+  api_key: "whatever"  # Mandatory, fake api_key with a random string you like :-)
 ```
 
 ### How to use OpenRouter models?