Remove "Preview 4" and replace with 16.0

Author: davkean

Diff for: docs/repo/roadmap.md

@@ -6,7 +6,7 @@ The first release of the project system ("15.0") was heavily focused on supporti
 |-------|--------|--------|--------|
 |[15.0.x](https://github.com/dotnet/project-system/milestone/4)|[15.0.x](https://github.com/dotnet/project-system/tree/dev15.0.x)|Visual Studio 2017|This release is considered done and will only be patched for security-related issues.
 |[15.9](https://github.com/dotnet/project-system/milestone/21)|[15.9.x](https://github.com/dotnet/project-system/tree/dev15.9.x)|Visual Studio 2017|This release is considered done, and only impactful bugs, crashes and hangs that block _major_ scenarios will be taken.
-|[16.0 Preview 4](https://github.com/dotnet/project-system/milestone/26)|[16.0.x](https://github.com/dotnet/project-system/tree/dev16.0.x)|Visual Studio 2019|This release is considered done, and only impactful bugs, crashes and hangs that block _major_ and _minor_ scenarios will be taken.
+|[16.0](https://github.com/dotnet/project-system/milestone/12)|[16.0.x](https://github.com/dotnet/project-system/tree/dev16.0.x)|Visual Studio 2019|This release is considered done, and only impactful bugs, crashes and hangs that block _major_ and _minor_ scenarios will be taken.
 |[16.1](https://github.com/dotnet/project-system/milestone/24)|[master](https://github.com/dotnet/project-system/tree/master)|Visual Studio 2019|All other feature work.
 |[16.x](https://github.com/dotnet/project-system/milestone/25)|N/A|Visual Studio 2019| This release will be focused on [feature parity](https://github.com/dotnet/project-system/labels/Parity-Legacy) with the legacy project system, support for [.NET Core 3.0](https://github.com/dotnet/project-system/labels/Feature-.NET-Core), [WinForms](https://github.com/dotnet/project-system/labels/Feature-WinForms) and [WPF](https://github.com/dotnet/project-system/labels/Feature-XAML).
 |[Backlog](https://github.com/dotnet/project-system/milestone/5)|none| |Uncommitted features/bugs.