Add configuration to appsettings.json with nuget package

I have created a nuget package where I am in need of adding a section to appsettings.json, or add my own configuration file that is copied into the application, but I am unable to figure out how.

I want this:

{
 "mysection" : 
  { 
        "value1": "value, 
        "value2": "value"
  }
}

to be added to the configuration file, or a file containing this to be copied when downloading the nuget package. We are using Visual Studio Team Services to build and host the nuget packages.