.Net: Update Concepts README for new Prompt samples (#6173)

### Motivation and Context

Closes #6166 

### Description

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### Contribution Checklist

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- [ ] The code builds clean without any errors or warnings
- [ ] The PR follows the [SK Contribution
Guidelines](https:/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
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script](https:/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄

.vscode/settings.json

@@ -72,6 +72,7 @@
  },
  "cSpell.words": [
  "Partitioner",
+ "Prompty",
  "SKEXP"
  ],
  "[java]": {

dotnet/samples/Concepts/README.md

@@ -117,10 +117,15 @@ Down below you can find the code snippets that demonstrate the usage of many Sem
 
 - [ChatCompletionPrompts](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/PromptTemplates/ChatCompletionPrompts.cs)
 - [ChatWithPrompts](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/PromptTemplates/ChatWithPrompts.cs)
+- [LiquidPrompts](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/PromptTemplates/LiquidPrompts.cs)
 - [MultiplePromptTemplates](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/PromptTemplates/MultiplePromptTemplates.cs)
 - [PromptFunctionsWithChatGPT](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/PromptTemplates/PromptFunctionsWithChatGPT.cs)
 - [TemplateLanguage](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/PromptTemplates/TemplateLanguage.cs)
 
+## Prompty - Using Prompty file format to [import prompt functions](https:/microsoft/semantic-kernel/blob/main/dotnet/src/Functions/Functions.Prompty/Extensions/PromptyKernelExtensions.cs)
+
+- [PromptyFunction](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/Prompty/PromptyFunction.cs)
+
 ## RAG - Retrieval-Augmented Generation
 
 - [WithFunctionCallingStepwisePlanner](https:/microsoft/semantic-kernel/blob/main/dotnet/samples/Concepts/RAG/WithFunctionCallingStepwisePlanner.cs)