Update supported-model-types.mdx

slight wording update

Author: kathayl

src/content/docs/ai-gateway/guardrails/supported-model-types.mdx

@@ -13,6 +13,6 @@ AI Gateway's Guardrails detects the type of AI model being used and applies safe
 
 :::note[Note]
 
-Guardrails does not support streaming.
+Guardrails does not yet support streaming responses. Support for streaming is planned for a future update.
 
 :::