docs: corrected command to run ngrok
docs: corrected command to run ngrok

friasdesign/frontend-nanodegree-mobile-portfolio,glennbacon/frontend-nanodegree-mobile-portfolio,friasdesign/frontend-nanodegree-mobile-portfolio,glennbacon/frontend-nanodegree-mobile-portfolio,DavidThorpe71/frontend-nanodegree-mobile-portfolio,hugo626/frontend-nanodegree-mobile-portfolio,hugo626/frontend-nanodegree-mobile-portfolio,h-n-y/udacity-page-optimization,DavidThorpe71/frontend-nanodegree-mobile-portfolio,brianquach/udacity-nano-front-optimization,petarmihaylov/UFEWDN-P4-Website-Optimization,h-n-y/udacity-page-optimization,petarmihaylov/UFEWDN-P4-Website-Optimization