Fix offscreen navbar issues #269 and #270

@grayghostvisuals take a look at this PR.

This are the lines that allows to close the nav by clicking outside the nav. https://github.com/WellingGuzman/Effeckt.css/blob/0e01664661972718592824b0b6b32e5ac9ef5938/js/modules/off-screen-nav.js#L41-L49

Thanks