docs(streaming): update streaming configuration documentation

feature: #1538
Revise streaming docs to clarify usage of stream_async(), remove
outdated global streaming config, and add CLI usage instructions.
Explain output rails streaming requirements and deprecation of
StreamingHandler. Improve examples and guidance for token usage
tracking.

Author: Pouyanpi

docs/configure-rails/yaml-schema/streaming/global-streaming.md

@@ -1,50 +1,33 @@
 ---
-title: Global Streaming
-description: Enable streaming mode for LLM token generation in config.yml.
+title: Streaming
+description: Using streaming mode for LLM token generation in NeMo Guardrails.
 ---
 
-# Global Streaming
+# Streaming
 
-Enable streaming mode for the main LLM generation at the top level of `config.yml`.
+NeMo Guardrails supports streaming LLM responses via the `stream_async()` method. No configuration is required to enable streaming—simply use `stream_async()` instead of `generate_async()`.
 
-## Configuration
+## Basic Usage
 
-```yaml
-streaming: True
-```
-
-## What It Does
-
-When enabled, global streaming:
+```python
+from nemoguardrails import LLMRails, RailsConfig
 
-- Sets `streaming = True` on the underlying LLM model
-- Enables `stream_usage = True` for token usage tracking
-- Allows using the `stream_async()` method on `LLMRails`
-- Makes the LLM produce tokens incrementally instead of all at once
+config = RailsConfig.from_path("./config")
+rails = LLMRails(config)
 
-## Default
+messages = [{"role": "user", "content": "Hello!"}]
 
-`False`
+async for chunk in rails.stream_async(messages=messages):
+    print(chunk, end="", flush=True)
+```
 
 ---
 
-## When to Use
-
-### Streaming Without Output Rails
-
-If you do not have output rails configured, only global streaming is needed:
-
-```yaml
-streaming: True
-```
-
-### Streaming With Output Rails
+## Streaming With Output Rails
 
-When using output rails with streaming, you must also configure [output rail streaming](output-rail-streaming.md):
+When using output rails with streaming, you must configure [output rail streaming](output-rail-streaming.md):
 
 ```yaml
-streaming: True
-
 rails:
   output:
     flows:
@@ -53,27 +36,15 @@ rails:
       enabled: True
 ```
 
----
+If output rails are configured but `rails.output.streaming.enabled` is not set to `True`, calling `stream_async()` will raise an `StreamingNotSupportedError`.
 
-## Python API Usage
+---
 
-### Simple Streaming
+## Streaming With Handler (Deprecated)
 
-```python
-from nemoguardrails import LLMRails, RailsConfig
-
-config = RailsConfig.from_path("./config")
-rails = LLMRails(config)
+> **Warning:** Using `StreamingHandler` directly is deprecated and will be removed in a future release. Use `stream_async()` instead.
 
-messages = [{"role": "user", "content": "Hello!"}]
-
-async for chunk in rails.stream_async(messages=messages):
-    print(chunk, end="", flush=True)
-```
-
-### Streaming With Handler
-
-For more control, use a `StreamingHandler`:
+For advanced use cases requiring more control over token processing, you can use a `StreamingHandler` with `generate_async()`:
 
 ```python
 from nemoguardrails import LLMRails, RailsConfig
@@ -113,9 +84,19 @@ Enable streaming in the request body by setting `stream` to `true`:
 
 ---
 
+## CLI Usage
+
+Use the `--streaming` flag with the chat command:
+
+```bash
+nemoguardrails chat path/to/config --streaming
+```
+
+---
+
 ## Token Usage Tracking
 
-When streaming is enabled, NeMo Guardrails automatically enables token usage tracking by setting `stream_usage = True` for the underlying LLM model.
+When using `stream_async()`, NeMo Guardrails automatically enables token usage tracking by setting `stream_usage = True` on the underlying LLM model.
 
 Access token usage through the `log` generation option: