title: How to launch VSCode to diff two files via protocol handler
body: <p>I'm writing a UWP app and want to launch VSCode to diff two files, like you can do code.cmd --diff a.txt b.txt.
  However because this is in a UWP app, I can't just start a process, instead I have to launch a protocol/Uri. 
  I know there is a protocol handler to clone a repo, is there a protocol handler to diff two files?
  Thanks!</p>