initial updates for 16.4

Author: TerryGLee

docs/ide/whats-new-visual-studio-2019.md

@@ -2,7 +2,7 @@
 title: "What's new in Visual Studio 2019"
 titleSuffix: ""
 description: "Learn about the new features in Visual Studio 2019."
-ms.date: 09/24/2019
+ms.date: 12/02/2019
 helpviewer_keywords:
   - "Visual Studio, what's new"
   - "what's new [Visual Studio]"
@@ -18,7 +18,7 @@ ms.workload:
 ---
 # What's new in Visual Studio 2019
 
-**Updated for the [16.3 release](/visualstudio/releases/2019/release-notes/)**
+**Updated for the [16.4 release](/visualstudio/releases/2019/release-notes/)**
 
 >[!div class="button"]
 >[Download Visual Studio 2019](https://visualstudio.microsoft.com/downloads)