Update media-streaming.md

Author: valindrae

articles/communication-services/concepts/voice-video-calling/media-streaming.md

@@ -9,7 +9,7 @@ ms.author: kpunjabi
 ms.custom: private_preview
 ---
 
-# Media streaming overview - Audio subscription
+# Media streaming overview - audio subscription
 
 > [!IMPORTANT]
 > Functionality described on this document is currently in private preview. Private preview includes access to SDKs and documentation for testing purposes that are not yet available publicly.