Add new Getting Started page

Modified content in start-en.hbs to match the new theme, 
Added page specific css in content/_base,scss
Modified colours in main/_base.scss and footer/_base.scss
Modified link colours in _variables.scss 
To keep this simple, just use the conditional for the class. For example:
```
	<body vocab="http://schema.org/" typeof="WebPage"{{#is newdesign "true"}} class="newdesign"{{/is}}>
```