Cookbook - initial commit for 508 compliancy

##### Note:
I initially submitted an issue for this same topic here: https://github.com/emberjs/website/issues/1630
Realized I did it wrong so this is me attempting to correct it. 

### Title: 
##### A general guide to achieving 508 compliance with an Ember.js app. 

### Problem:
Single page apps can make it difficult to program for those with disabilities. The community needs a basic launchpad to discuses how to handle programming for this demographic within an Ember.js app.

Relevant book on the subject:
[Accessibility Handbook: Making 508 Compliant Websites](http://shop.oreilly.com/product/0636920024514.do)
Small Discuss Tread:
[Acccessibility in emberjs](http://discuss.emberjs.com/t/acccessibility-in-emberjs/4739)

### Solution Statement
### Discussion