[feat] .NET integration location

[attilah]

@hellovai As we discussed pushed my .NET CFFI integration to the following repos:

• BAML side: https://github.com/attilah/baml/tree/feat/csharp
• .NET side: https://github.com/attilah/bamldotnet

[linear]

BAML-527

[sxlijin]

Thanks! Really appreciate you doing all this 🙏