title: How to add a property to project.json after nuget package installation?
body: <p>I have a NuGet package that contains a .NET Core library let's call it <em>calculator</em>, whenever a client project installs my package a configuration property needs to be added in an existing configuration section in the client's project <code>project.json</code>.</p>
  
  <p>Example:<br/>
  This is the client's initial <code>project.json</code>:</p>
  
  <pre><code>{
      ...
      "confSection": {
          "intialConfig": true
      },
      ...
  }
  </code></pre>
  
  <p>and this is what it needs to look like after installing the library</p>
  
  <pre><code>    {
              ...
              "confSection": {
                  "intialConfig": true,
                  "addedConfig": true
              },
              "dependencies": {
                  "calculator": "0.1.0"
               }
              ...
  }
  </code></pre>
  
  <p><strong>How to achieve this?</strong><br/>
  <strong>Is there a post install script facility in NuGet that will allow to write scripts that perform the preceding?</strong></p>