[Changed] Suggested add code analyzers.

Suggested add [Roslyn Analyzers](https://github.com/dotnet/roslyn-analyzers) and [StyleCop Analyzers](https://github.com/DotNetAnalyzers/StyleCopAnalyzers) and [SonarAnalyzer.CSharp](https://www.nuget.org/packages/SonarAnalyzer.CSharp/) to improve code quality and code style.