fix tests default model, docfixes [skip ci]

docs/NODE_GUIDE.md

@@ -8,13 +8,12 @@ Running a Dria Compute Node is pretty straightforward! You can either follow the
 
 Depending the AI models of your choice, you may have to install software:
 
-- **OpenAI models**: you don't have to do anything!
-- **Ollama models**: you have to install Ollama
+- **OpenAI models**: you don't have to install anything, we just need an `OPENAI_API_KEY`!
+- **Ollama models**: you have to install Ollama, see [download instructions here](https://ollama.com/download). After installing, confirm you have it with:
 
-```sh
-# prints Ollama version
-ollama -v
-```
+  ```sh
+  ollama --version
+  ```
 
 ### Hardware
 

src/config/mod.rs

@@ -192,7 +192,7 @@ impl Default for DriaComputeNodeConfig {
             "DKN_WALLET_SECRET_KEY",
             "6e6f64656e6f64656e6f64656e6f64656e6f64656e6f64656e6f64656e6f6465",
         );
-        env::set_var("DKN_MODELS", "phi3:3.8b");
+        env::set_var("DKN_MODELS", "gpt-3.5-turbo");
 
         Self::new()
     }