title: Reference variables in appsettings.json for NLog connection string
body: <p>I have this <code>appsettings.json</code> file in my project that looks like this:</p>
  
  <pre><code>{
    "ConnectionStrings": {
      "MyConnectionString": "Server=SQLSERVER;Database=MyDatabse;Trusted_Connection=True;"
    },
    "NLog": {
      "targets": {
        "database": {
          "type": "Database",
          "dbProvider": "System.Data.SqlClient",
          "connectionString": "Server=SQLSERVER;Database=MyDatabse;Trusted_Connection=True;"
        }
      }
    }
  }
  </code></pre>
  
  <p>I do not want to write my connection string multiple places. Can I somehow reference the previous connection string?</p>
  
  <p>I have already tried: <code>"connectionString": "${appsetting:name=ConnectionStrings.MyConnectionString}"</code>, which is not working.</p>