quote update for chokidar-cmd input
quote update for chokidar-cmd input

fixes https://github.com/mozilla/learning.mozilla.org/issues/2187 by using double quote for the chokidar command to trigger on changes
mozilla/teach.webmaker.org,mozilla/teach.mozilla.org,mozilla/teach.webmaker.org,mozilla/learning.mozilla.org,mozilla/teach.mozilla.org