Nightwatch JS and Microsoft WebDriver for Microsoft Edge

So...

Attempting to get tests running following the Nighwatch.js docs. Followed the instructions to the letter and still no joy.

https://nightwatchjs.org/gettingstarted#microsoft-webdriver

So because Microsoft don't make the .exe available - WebDriver for Microsoft Edge is now a Windows Feature on Demand. To install run the following in an elevated command prompt:

DISM.exe /Online /Add-Capability /CapabilityName:Microsoft.WebDriver~~~~0.0.1.0

My config file nightwatch.json is as Nightwatch.s js docs have told me to configure it:

{
  "test_settings" : {
    "default" : {
      "selenium_port"  : 17556,
      "selenium_host"  : "localhost",
      "default_path_prefix" : "",

      "desiredCapabilities": {
        "browserName": "MicrosoftEdge",
        "acceptSslCerts": true
      }
    }
  }
}

I am running Edge 18.17763 and on the Microsoft docs it states "Microsoft WebDriver for Microsoft Edge (EdgeHTML) versions 18 and 19 is a Windows Feature on Demand which ensures that it’s always up to date automatically and enables some new ways to get Microsoft WebDriver. To get started you will have to enable Developer Mode:"

My tests will not launch when I write the 'nightwatch' command. Please help.