Add release package for .nuget

[ahelmbr]

A gradle plugin for .nuget can be found here: https://github.com/Itiviti/gradle-nuget-plugin

Add the package in the same way like the others Add documentation

buildscript {
    repositories {
      mavenCentral()
    }

    dependencies {
        classpath "com.ullink.gradle:gradle-nuget-plugin:2.17"
    }
}

apply plugin: 'nuget'