docs: add reference to dotnet lts images (#1031)

Author: ghuntley

src/docs/languages/dotnet.md

@@ -1,30 +1,58 @@
 # .NET in Gitpod
 
-## Example Repositories
+It's easy to set up your .NET project in Gitpod.
 
+## .NET Versions
 
-<div class="table-container">
+To get all the .NET tools that you need pre-installed in your Gitpod workspaces choose the appropriate base image for your [.gitpod.yml](https://www.gitpod.io/docs/config-gitpod-file/):
 
-| Repository | Description | Try it |
-|------|----------------|-----------|
-|[dotnetcore](https://github.com/gitpod-io/dotnetcore)|C# .NET Core template|[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/gitpod-io/dotnetcore)|
-|[uno](https://github.com/unoplatform/uno)|Build Mobile, Desktop and WebAssembly apps with C# and XAML|[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/unoplatform/uno)|
-|[uno.quickstart](https://github.com/unoplatform/uno.quickstart)|An Uno "Hello world!" project using Windows UWP, iOS, Android and WebAssembly|[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/unoplatform/uno.quickstart)|
+### Current
 
-</div>
+For the latest .NET SDK and Runtime:
 
-## Installing the .NET Tools
 
-To get all the .NET tools that you need pre-installed in your Gitpod workspaces, use the following base image in your [.gitpod.yml](https://www.gitpod.io/docs/config-gitpod-file/):
 ```YAML
 image: gitpod/workspace-dotnet
 ```
 
-If your project requires a GUI or Virtual Desktop, please use this image instead:
+If your project requires a GUI or Virtual Desktop:
+
 ```YAML
 image: gitpod/workspace-dotnet-vnc
 ```
-This will give you a full GUI Virtual Desktop for your .NET application! The Virtual Desktop will be running on port `6080`.
+
+This will give you a full GUI Virtual Desktop running on port `6080` for your .NET application.
+
+
+### Long Term Support (LTS)
+
+For the latest .NET SDK and Runtime with [long term support (LTS)](https://dotnet.microsoft.com/platform/support/policy/dotnet-core):
+
+```YAML
+image: gitpod/workspace-dotnet-lts
+```
+
+If your project requires a GUI or Virtual Desktop:
+
+```YAML
+image: gitpod/workspace-dotnet-lts-vnc
+```
+
+This will give you a full GUI Virtual Desktop running on port `6080` for your .NET application.
+
+
+## Example Repositories
+
+
+<div class="table-container">
+
+| Repository | Description | Try it |
+|------|----------------|-----------|
+|[dotnetcore](https://github.com/gitpod-io/dotnetcore)|C# .NET Core template|[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/gitpod-io/dotnetcore)|
+|[uno](https://github.com/unoplatform/uno)|Build Mobile, Desktop and WebAssembly apps with C# and XAML|[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/unoplatform/uno)|
+|[uno.quickstart](https://github.com/unoplatform/uno.quickstart)|An Uno "Hello world!" project using Windows UWP, iOS, Android and WebAssembly|[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/unoplatform/uno.quickstart)|
+
+</div>
 
 ## Compiling .NET Code in Gitpod