message: Update changelog with latest Razor changes
diff: -## Known Issues in 1.17.0
  +## Known Issues in 1.17.1
  * Known limitations with the preview Razor (cshtml) language service to be addressed in a future release:
  * Only ASP.NET Core projects are supported (no support for ASP.NET projects)
  * Limited support for colorization
  * Loss of HTML completions following C# less than (`<`) operator
  * Error squiggles misaligned for expressions near the start of a new line
  - * Leaving Razor files open for a significant period of time results in loss of Razor C# tooling on macOS
  * Incorrect errors in Blazor projects for event bindings
  + * Emmet based abbreviation expansion is not yet supported
  * There currently is no completion support for package references in csproj files. ([#1156](https://github.com/OmniSharp/omnisharp-vscode/issues/1156))
  * As an alternative, consider installing the [MSBuild Project Tools](https://marketplace.visualstudio.com/items?itemName=tintoy.msbuild-project-tools) extension by @tintoy.
  +## 1.17.1
  +
  +* Updated Razor language service to fix various Razor editing reliability issues. For details see https://github.com/aspnet/Razor.VSCode/releases/tag/1.0.0-alpha2.
  +
  ## 1.17.0 (October 31, 2018)
  * Added preview Razor (cshtml) language service with support for C# completions and diagnostics in ASP.NET Core projects. Please report issues with the preview Razor tooling on the [aspnet/Razor.VSCode](https://github.com/aspnet/Razor.VSCode/issues) repo. To disable the preview Razor tooling set the "razor.disabled" setting to `true`. (PR: [2554](https://github.com/OmniSharp/omnisharp-vscode/pull/2554))
  