title: Reading and Writing keys to appsettings in WebConfigEditor
body: <p>My project contains web.config file and an external appSettings file. I am making a WebConfig Editor that has options to Read AppSettings key from web.config and external appSetting file to display them on webPage.
  Also, I am allowing user to delete any key by clicking on Remove button.
  Moreover, user can also update any key's value  by clicking on update button.Or
  he can also insert new key by clicking on Add New Key button.</p>
  
  <p>The key issue I am facing is that whenfever I try to add a new key , it gets inserted into
  web.config file as expected , but at the same time it adds all the keys present in external appSettings file into web.config ( which is abrupt behavior). </p>
  
  <p>How to stop this migration of keys from external appSettings file to web.config on any key's update / delete/ add function?</p>