ASP.NET MVC Web.config move AppSettings to separate file

Create a new config file name PrivateSettings.config.

<appSettings>
  <add key="UnobtrusiveJavaScriptEnabled" value="true" />
</appSettings>

Add the path to your extra appSettings file to the web.config appSettings tag.

<appSettings file="PrivateSettings.config">
  ...
</appSetting>