Create guidelines.md

Basic guidelines for NODE API
Update guidelines.md
Update guidelines.md
Update guidelines.md
Update .jshintrc
Nginx cross-site configuration.

Nginx configuration to pass through the cross-site validation.
refactor structure of folders and guides
more refactor of node guides
typo on link
add some modules to Popular modules section
Refactors Testing guide.
fix link to protractor
adding nodemailer guide