Add existing windows container description to the samples Readme

Author: Greenie0506

samples/README.md

@@ -1,4 +1,5 @@
 # Azure Dev Spaces Samples
 These sample projects are used in Azure Dev Spaces documentation to demonstrate product capabilities.
 1. **BikeSharingApp**: A large application implemented as multiple microservices written in various languages. This provides a good example of what Azure Dev Spaces can provide to a team developing large applications. For documentation see: <https://docs.microsoft.com/en-us/azure/dev-spaces/quickstart-team-development>
-1. **dotnetcore/golang/java/nodejs**: Simple applications to demonstrate how Azure Dev Spaces can help developers writing code in specific languages. For documentation see: <https://aka.ms/get-azds>
+1. **dotnetcore/golang/java/nodejs**: Simple applications to demonstrate how Azure Dev Spaces can help developers writing code in specific languages. For documentation see: <https://aka.ms/get-azds>
+1. **existingWindowsBackend**: Simple application to demonstrate how Azure Dev Spaces can be used when working in a mixed cluster running both Linux containers as well as Windows containers. For documentation see: <https://aka.ms/existing-windows-containers>