add extension to readme

Author: tebjan

README.md

@@ -1,6 +1,28 @@
 # Shader Explorer for Stride
 A tool showing the [built-in shaders](https://doc.stride3d.net/latest/en/manual/graphics/effects-and-shaders/shading-language/index.html) of the [Stride game engine](https://stride3d.net/) and [vvvv gamma](https://vvvv.org/) and their inheritance hierarchy.
 
+## VS Code Extension
+
+<a href="https://marketplace.visualstudio.com/items?itemName=tebjan.sdsl">
+  <img src="VSCode/vscode-extension/icons/icon.png" alt="Stride Shader Tools" width="128px"/>
+</a>
+
+**[Stride Shader Tools](https://marketplace.visualstudio.com/items?itemName=tebjan.sdsl)** - VS Code extension for SDSL shader development with:
+
+* Syntax highlighting for `.sdsl` files
+* IntelliSense with completions for shaders, variables, and methods
+* Hover info showing inherited members and type information
+* Go-to-definition for base shaders
+* Diagnostics for undefined identifiers with quick-fix suggestions
+* Inheritance tree view panel
+* Template shader support
+
+Install from the [VS Code Marketplace](https://marketplace.visualstudio.com/items?itemName=tebjan.sdsl).
+
+---
+
+## Desktop Application
+
 Parses all shaders in user\\.nuget\packages\stride.packagename\latest-version
 
 Features: