Update dotnet-developer-projects.md
Update dotnet-developer-projects.md

I've added one library for application protection (SKGL), one for expression parser (Mathos Parser) with support for expression to IL conversion, and a mathematical library (Mathos Core Library).
velyo/dotnet,Microsoft/dotnet,Microsoft/dotnet,punker76/dotnet,richlander/dotnet,velyo/dotnet,BruceForstall/dotnet,BruceForstall/dotnet,richlander/dotnet,690486439/dotnet,punker76/dotnet