[C#] automatically generate nuspec file

[wing328]

Description

We want to automatically generate nuspec file (example) for C# API client so that the C# API client can be easily packaged into NuGet library using the following command:

nuget pack <project_file> -OutputDirectory <temp_path>

Ref: https://docs.nuget.org/create/nuspec-reference

Swagger-codegen version

Latest master

Suggest a Fix/Solution

If anyone wants to work on this, please reply to let us know. Thanks!

[jimschubert]

I can pick this up.

[wing328]

Closed via #4576. Thanks for the contribution from @jimschubert