EdgeDriver doc needs updating

[garg3133]

When the user selects Edge as one of the browser, we provide a doc link to the user at the end of the instructions where they can go and learn how to set up edge driver for test run: https://nightwatchjs.org/guide/browser-drivers-setup/edgedriver.html

But the doc page has been changed and needs to be updated again with instructions on how to setup edge driver for normal test run using Nightwatch (and not local selenium-server).

Related discussion: nightwatchjs/nightwatch-docs#166 (comment)