Add copy step to quickstart

Just adding the copy `upd.install` step to the quickstart. Without this step if someone were to follow the quickstart the updater would download, unpack and run the latest app from temp dir but never copy itself to the original directory. 

Once I figured out this step all worked amazingly well for my project:
https://github.com/digitalmaster/MongoCMS/blob/master/js/utils/autoupdate.js