tts update

Author: eric-urban

articles/cognitive-services/Speech-Service/releasenotes.md

@@ -21,6 +21,7 @@ See below for information about new features and other changes to the Speech ser
 
 ## Recent highlights
 
+* Text-to-speech Batch synthesis API is available in public preview.
 * Speech-to-text REST API version 3.1 is generally available.
 * Speech SDK 1.24.0 and Speech CLI 1.24.0 were released in October 2022. 
 * Speech-to-text and text-to-speech container versions were updated in October 2022.