Bug: inconsistent documentation around servers running (#472)

Signed-off-by: Brian Yu <bxyu@nvidia.com>

Author: bxyu-nvidia

docs/get-started/rollout-collection.md

@@ -66,7 +66,7 @@ responses_api_models/openai_model/configs/openai_model.yaml"
 ng_run "+config_paths=[${config_paths}]"
 ```
 
-**✅ Success Check**: You should see 3 servers running including the `simple_weather_simple_agent`.
+**✅ Success Check**: You should see 3 Gym servers running including the `simple_weather_simple_agent`, along with the head server.
 
 ## 3. Generate Rollouts