Hybrid projects

# Including CSS best practices for Hybrid App projects

Status: **Up For Review**

Reviewers: @kpeatt @rosshojo @jeffkamo @mobifydave @jansepar 
JIRA: https://mobify.atlassian.net/browse/GOLD-1164

## Changes
- Initialized new page in the css code styles and filled in what we currently have established as best practices.
I guess the thing I'm thinking about is, if you were to start fresh, would you really want separate css files for different platforms? For example, if you're building a brand new responsive site - AFAIK it's not a recommended practice to have separate css files for say, desktop vs mobile. Or for iOS Web vs Android Web. So why are we considering it for apps? What makes apps so special?

The only thing I can think of us that it's easier to have separate files when building off an existing mobify.js/adaptive.js sites, because then you don't need to worry as much about how you are effecting the mobile site.