readme : add C#/.NET bindings repo (#1409)

README.md

@@ -87,6 +87,7 @@ as the main playground for developing new features for the [ggml](https://github
 - Go: [go-skynet/go-llama.cpp](https://github.com/go-skynet/go-llama.cpp)
 - Node.js: [hlhr202/llama-node](https://github.com/hlhr202/llama-node)
 - Ruby: [yoshoku/llama_cpp.rb](https://github.com/yoshoku/llama_cpp.rb)
+- C#/.NET: [SciSharp/LLamaSharp](https://github.com/SciSharp/LLamaSharp)
 
 **UI:**